A picture of the glowing skyline of London at night, taken by the author from the London Eye.

A whole universe of tiny stars.

Building an ETF Universe: Selection First Pass

money-machine Sep 9, 2025

We are building a very simple version zero of a money machine: a long-only ETF portfolio, managed without explicit leverage (though with some implicit leverage via a mortgage), based in the United Kingdom through the broker Hargreaves Lansdown. Holdings will only be adjusted once per quarter. These are the very practical constraints and cornerstones for building a particular type of money machine that allocates wealth holdings between a selection of 'productive assets' or 'forms of value representation' such that we gain a robust amount of diversification, thus increasing risk adjusted skill of this 'constant bullish' investment hypothesis.

This exercise is not only a first prototype for systematic portfolio design but also a concrete example of the more general problem faced by anyone seeking to manage their own retirement investments.

The allocation framework we are implementing is a version of hierarchical risk parity. Assets are grouped into categories, and risk is distributed across these categories in proportion to their position in the hierarchy. Portfolio adjustments over time are driven only by changes in asset risk and market prices.

At this initial stage, no active signals are incorporated. Implicitly, we assume that each unit of risk is associated with the same expected return, regardless of asset class. ETFs are chosen as the building blocks, since they provide simple, cost-effective exposure to a broad range of underlying markets.

The immediate task we tackle in this article is to select a universe of suitable ETFs that represent the layers of our intended hierarchy. Using ETF listing and screening platforms such as justETF.com and Morningstar, we compile selective lists of high-quality ETFs across a wide set of categories. From these candidates, we can construct a hierarchical risk parity portfolio and investigate statistically derived hierarchies.

Bottom-Up: Starting from the ETF Market

A natural first step is to explore the structure that ETF providers and listing platforms already present. The website justETF.com offers a screening tool that groups ETFs into broad categories and subcategories.

Restricting attention to London-listed ETFs (to ensure availability through Hargreaves Lansdown), we begin with the highest-level classification:

All Asset Classes (2030)

    • Equity (1297)
    • Bonds (579)
    • Precious Metals (39)
    • Commodities (77)
    • Real Estate (24)
    • Money Market (14)

The numbers in brackets show the number of different ETFs available in each of the categories.

We are ignoring the Money Market category, as this would be holdings to keep un-invested cash, but we are planning for an always fully invested strategy, so we do not need the money market instruments.

Real Estate comprises ETFs that hold companies that manage real estate. While this is a productive asset class that generates 'yield' from rental income, we ignore it for our portfolio, as we already have an overweight in real estate from physical holdings.

The Commodities ETFs are providing exposure to (usually front month) futures of a wide range of commodities. These are not in themselves productive assets, but are produced and consumed as part of industrial processes. Their value is subject to variations in the supply demand balance and there is no natural long-bias, thus they are much better suited for a long-short signal driven portfolio, which can access them via futures, hence we are ignoring them as well in our portfolio.

We are investigating the sub-categories in each of the remaining asset classes (Precious Metals, Equity, Bonds), identifying the different underlying exposures, and selecting a set of ETFs to use going forward to represent these exposures for our ETF universe.

Selection Criteria and aim

This is the first round of selecting relevant indices and ETF expressions. At this stage we are not yet settling on a single hierarchy or index providers, rather we are selecting all indices that have 'best-in-class' ETF expressions, within a range of specialisation and diversification that is relevant for portfolios ranging from very small to significant, while still not large enough that they would eschew ETFs for direct single instrument expressions, or run more sophisticated strategies by default.

To select admissible ETFs and indices we are requiring ETFs with TER <0.5%, a fund size >£100m, and a full replication or optimised sampling replication method (no unfunded swaps).

With our account sizes we will end up with a couple dozen holdings at maximum, so we are investigating hierarchy levels down to country level, but are not distinguishing sectors within countries, or different maturities in bond ETFs.

If multiple ETFs are expressing the same index, we will pick the cheaper, bigger, longer history version, in a lexicographic ordering.

From Criteria to a Working Universe

The objective of this first pass is deliberately modest: define a clean, tradeable ETF universe that respects our constraints (HL venue, GBP base, quarterly rebalancing, no explicit leverage) and is broad enough to support a hierarchy-based allocation. The selections above are therefore inputs, not outcomes. They specify what we can own, not what we must own.

Several scope limits are intentional. We prioritise large, liquid, low-cost funds with transparent replication and sufficient history. We do not resolve overlaps across index families at this stage, nor do we enforce perfect regional partitioning or factor neutrality. We also defer thematic tilts, sector detail, and ESG/Paris-aligned construction to a dedicated analysis, so that the baseline remains methodologically plain and reproducible.

The next step is quantitative. Using the universe below, we will:

  • collect and validate return, volatility, and correlation data;
  • construct top-down hierarchies (by issuer type, region, currency) and bottom-up hierarchies (statistical clustering, PCA loadings);
  • compare resulting trees and choose a practical structure for hierarchical risk parity sizing under quarterly rebalancing.

What follows is the consolidated table set: the ETF Universe v0. It is the reference inventory for all subsequent tests and allocations. Each entry lists index, ETF, ISIN, ticker, and key notes. As we iterate, individual line items may change, but the selection principles and the role of this universe—as the stable substrate for a version-zero money machine—remain the same.

Precious Metals

The 39 instruments available in this category relate to only five underlying exposures: gold, silver, platinum, palladium, and a single instrument for rhodium.

Unlike equities or bonds, precious metals are not productive assets. They do not generate cash flows or yield. Instead, they are best understood as alternative stores of value, whose price is determined by scarcity, investor demand, and (to a lesser extent) industrial use. This also marks the definitional distinction from industrial metals such as copper or nickel, which are primarily used in production processes.

Most of the listed products are structured as Exchange Traded Commodities (ETCs) rather than ETFs, because European UCITS rules prohibit funds that track a single undiversified commodity. These ETCs may be:

  • Physically backed, where each share is secured by metal held in vaults (common for gold and silver).
  • Synthetic, where exposure is obtained via futures contracts (more common for platinum and palladium).

From a portfolio perspective, precious metals can provide:

  • Diversification, as their drivers often differ from those of equities and bonds.
  • Inflation protection, particularly in the case of gold.
  • Crisis hedging, as demand for gold in particular tends to rise during periods of market stress.

However, their role is limited by the absence of yield and by the fact that long-term returns depend entirely on price appreciation.

In addition to simple Exchange traded commidities for the individual metals with fund currency in USD there are also some additional options available:

  • Currency hedged, removing the FX risk between the USD and the investors GBP home currency
  • A precious metals basket, giving exposure to Gold, Silver, Platinum, and Palladium in a fixed ratio, at higher annual cost
  • An actively managed fund, that adds an options strategy to gold holdings to generate yield

From this asset class we are selecting the following assets:

Exposure Name ISIN Ticker TER
Gold iShares Physical Gold ETC IE00B4ND3602 SGLN 0.12%
Silver iShares Physical Silver ETC IE00B4NCWG09 SSLN 0.20%
Platinum iShares Physical Platinum ETC IE00B4LHWP62 SPLT 0.20%
Palladium iShares Physical Palladium ETC IE00B4556L06 SPDM 0.20%
Precious Metals WisdomTree Physical Precious Metals JE00B1VS3W29 PHPP 0.44%

The chosen instruments balance low-cost single exposures with a diversified basket option, which can be used for small account sizes.

Equities

Equities can be sorted by region and country, each based on collections of companies in equity indices, such as the S&P500, FTS100, Eurostox600 etc. This grouping of Equity ETFs provides geographic diversification.

In addition there are equity ETFs that separate companies within a country, mostly the US by industry sector. For larger account sizes this can be a useful addition to spread the risk more evenly across sectors, compared to a capitalisation-based index like the S&P500.

There is also a, relatively new, set of theme-based ETFs, which can be used as equity-like alternative investments, which will give exposure to particular macro-economic themes or economic rationales, such as wood- or water- based companies, or energy transition, climate change, or others.

Finally there is the notion of active ETFs, which are implementing certain tactical allocation strategies, such as a momentum strategy, leveraged holdings, or even discretionary active management. We avoid these expressions on cost-basis (if at all we can have a glance over momentum ETFs).

We are first developing the regional and national index-based ETF hierarchy available on justETF (HL) and then an alternative/sector-based one.

Global

Global equity ETFs that track world-level indices provide the simplest way to gain diversified exposure across countries and regions. By following benchmarks such as the MSCI World, FTSE All-World, or Solactive Global Markets, these funds combine hundreds to thousands of stocks into a single tradeable vehicle. They are particularly useful when account size or simplicity dictates choosing just one equity allocation, or when an investor wants to pair a global basket with more focused exposures (for example, holding US equities directly and using a “World ex US” ETF for the rest). These instruments represent the top layer of the equity hierarchy, offering an efficient, low-cost entry point into international diversification.

Index Market Cap Coverage Regional Scope Use Case ISIN Ticker
MSCI World Large & Mid 23 Developed Markets Core global equity exposure, developed markets only IE000BI8OT95 MWRL
MSCI All Country World Index (ACWI) Large & Mid 23 Developed + 24 Emerging One-ticket global equity (developed + emerging) IE00B44Z5B48 ACWI
MSCI All Country World Investable Market (IMI) Large, Mid & Small 23 Developed + 24 Emerging Broadest global benchmark, includes small caps IE00B3YLTY66 IMID
FTSE All-World Large & Mid Developed + Emerging Alternative to ACWI, widely used for global coverage IE000716YHJ7 FWRG
FTSE Developed Large Developed Markets Simple developed-only exposure IE00BK5BQV03 VHVG
Solactive GBS Global Markets L&M Cap Large & Mid Developed + Emerging Low-cost global alternative to MSCI/FTSE IE0009HF1MK9 PACW
Solactive GBS Developed Markets L&M Cap Large & Mid Developed Markets Low-cost developed-only alternative IE000QIF5N15 MWOZ
MSCI World ex USA Large & Mid Developed Markets (ex USA) Combine with US exposure to build tailored global mix IE0006WW1TQ4 XMWX

Global - Themes

Thematic global equity ETFs offer targeted exposure to structural trends that cut across countries and industries. Rather than tracking broad benchmarks, these funds concentrate portfolios around specific themes such as artificial intelligence, clean energy, robotics, or healthcare innovation. They are equity-like in their behaviour, but serve as alternative expressions within a portfolio, allowing investors to place long-term bets on technological, demographic, or environmental shifts. Used sparingly, they can complement core holdings by adding distinct sources of potential growth and diversification at the global level.

For equities on global level we have the following themes:

Theme ISIN Ticker
Aging Population IE00BYZK4669 AGES
AI and Big Data IE00BGV5VN51 XAIX
Batteries IE00BKLF1R75 CHRG
Blockchain IE000RDRMSD1 BLKC
Clean Energy IE00BK5BCH80 RENG
Climate Change IE00BMDWYZ92 JPTC
Cyber Security IE00BG0J4C88 LOCK
Digitalisation IE00BYZK4883 DGIT
Future Mobility IE00BGL86Z12 GCAR
Hydrogen IE00BMYDM794 HTWG
Healthcare Innovation IE00BYZK4776 DRDR
Aerospace & Defense IE000U9ODG19 DFND
Infrastructure IE00BQWJFQ70 GIN
Private Equity IE0008ZGI5C1 FLPE
Robotics & Automation IE00BYZK4552 RBTX
Semiconductors IE00BMC38736 SMGB
Clean Water IE00BK5BC891 GLGG

Regional

Regional equity ETFs provide targeted exposure to specific continents or blocs, allowing investors to adjust global allocations or make focused bets on areas of strategic interest. They cover broad developed and emerging regions such as Europe, North America, and Asia-Pacific, while also offering more granular options like Latin America or World ex-China. In addition, many providers now offer ESG-enhanced or climate-aligned versions of the major regional benchmarks, giving investors the ability to tilt portfolios towards sustainability themes while maintaining diversified regional exposure.

Region Index Name Market Cap Coverage Regional Scope Use Case ISIN Ticker
Latin America MSCI EM Latin America 10/40 Large & Mid Emerging Latin America Single-ticket LatAm exposure with concentration caps IE00B27YCK28 LTAM
North America FTSE North America Large & Mid USA + Canada (developed) Broad North American equity exposure IE00BK5BQW10 VNRG
North America MSCI North America Large & Mid USA + Canada (developed) Alternative to FTSE; MSCI methodology IE00B14X4M10 INAA
North America FTSE North America All Cap Choice Large, Mid & Small USA + Canada (developed) Broader size coverage (incl. small caps) IE000O58J820 V3NB
Africa Coverage exists but investable ETFs too small/expensive
Eastern Europe Coverage exists but investable ETFs too small/expensive
Asia-Pacific MSCI Emerging Markets Asia Large & Mid Asian EM countries Captures growth dynamics of Asian emerging markets IE00B5L8K969 CEA1
Asia-Pacific MSCI Pacific Large & Mid Developed Pacific ex Japan Focused developed Asia-Pacific ex Japan IE00B52MJY50 CPJ1
Asia-Pacific FTSE Developed Asia Pacific ex Japan Large & Mid Developed Pacific ex Japan Alternative to MSCI Pacific IE00BK5BQZ41 VDPG
Asia-Pacific MSCI AC Far East ex Japan Large & Mid Developed + Emerging East Asia ex Japan Mixed DM+EM exposure in East Asia IE00BBQ2W338 HMAF
Asia-Pacific Solactive Core Developed Markets Pacific ex Japan L&M Large & Mid Developed Pacific ex Japan Low-cost developed ex Japan alternative IE00BFXR5W90 LGAG
Asia-Pacific FTSE Asia ex Japan ex China Large & Mid Asia (ex China, ex Japan) Regional diversification excluding two largest markets IE00BFWXDV39 FRQX
Emerging Mkts MSCI Emerging Markets IMI Large, Mid & Small Global EM Broadest EM benchmark incl. small caps IE00BKM4GZ66 EMIM
Emerging Mkts MSCI Emerging Markets ESG Enhanced Focus CTB Large & Mid Global EM EM exposure tilted towards ESG/low carbon IE00BHZPJ239 EDG2
Emerging Mkts MSCI Emerging Markets Large & Mid Global EM Standard EM benchmark IE000KCS7J59 HEMC
Emerging Mkts FTSE Emerging Large & Mid Global EM Alternative EM benchmark IE00BK5BR733 VFEG
Emerging Mkts MSCI Emerging Markets ex China Large & Mid Global EM ex China EM exposure without China dominance IE00BMG6Z448 EXCS
Emerging Mkts MSCI Emerging Markets Small Cap Small Cap Global EM Dedicated EM small-cap allocation IE00B48X4842 EMSM
Emerging Mkts Solactive GBS Emerging Markets L&M Large & Mid Global EM Low-cost EM alternative LU2300295123 PRAN
Europe STOXX Europe 600 Large, Mid & Small Pan-Europe (developed) Broad, liquid European benchmark LU0908500753 MEUD
Europe MSCI Europe Large & Mid 15 Developed European markets Standard MSCI European benchmark IE00B4K48X80 SMEA
Europe EURO STOXX 50 Large Eurozone (developed) Blue-chip Eurozone exposure IE00B53L3W79 CS51
Europe MSCI EMU Large & Mid Eurozone (developed) Alternative to EURO STOXX with MSCI methodology IE00B53QG562 CEU1
Europe MSCI Europe Screened Large & Mid Europe (developed) Europe ex controversial industries IE00BFNM3D14 SAEU
Europe FTSE Developed Europe Large & Mid Europe (developed) Alternative broad European benchmark IE00BK5BQX27 VEUA
Europe MSCI Europe Small Cap Small Cap Europe (developed) Dedicated European small-cap allocation LU0322253906 XXSC
Europe S&P Eurozone LargeMidCap Net Zero 2050 Paris-Aligned ESG Large & Mid Eurozone (developed) Paris Agreement-aligned ESG Eurozone exposure LU2195226068 PABG
Europe MSCI ACWI Select Climate 500 Europe Subset Large & Mid Europe (developed) Low-carbon ESG Europe allocation IE00BKLTRN76 RIEG

Countries

Country-level equity ETFs provide direct exposure to individual national markets, allowing investors to overweight or underweight specific countries relative to their share in global benchmarks. They are particularly useful for expressing structural views (e.g. growth in India or technology in the US), hedging home-country bias, or managing concentrated exposures in broad indices. Many countries offer both standard market-cap indices and ESG-screened or capped-weight variants, giving flexibility in how investors access local markets while maintaining diversification rules.

Country Index Name Market Cap Coverage Notes / Use Case ISIN Ticker
Australia MSCI Australia Large & Mid Standard benchmark for Australian equities IE00BD4TY451 AUST
Canada MSCI Canada Large & Mid Standard benchmark for Canadian equities LU0950672807 CANA
China FTSE China 30/18 Capped Large & Mid Broad China exposure with 30/18 caps IE00BHZRR147 FRCH
China MSCI China A Inclusion Large & Mid Focused on A-shares, linked to EM index inclusion LU0292109856 XX25
China MSCI China Universal Low Carbon Select 5% Issuer Capped Large & Mid ESG/low-carbon tilted China benchmark LU1953188833 CNSG
France CAC 40 Large 40 largest French stocks (blue-chip) FR0007052782 CACX
France MSCI France Large & Mid Broader French equity benchmark IE00BP3QZJ36 ISFR
Germany DAX 40 Large 40 largest German stocks (blue-chip) LU0274211480 XDAX
Germany MDAX Mid 50 German mid-cap stocks IE00BHJYDV33 PEAM
Germany FTSE Germany All Cap Large, Mid & Small Broad German equity benchmark IE00BG143G97 VGER
Germany DAX ESG Screened Large ESG-screened version of DAX, capped weights LU0838782315 XDDX
India FTSE India 30/18 Capped Large & Mid Broad India exposure with 30/18 caps IE00BHZRQZ17 FRIN
Italy FTSE MIB Large 40 largest Italian companies IE00B53L4X51 CMB1
Japan MSCI Japan IMI Large, Mid & Small Broadest Japan coverage (all caps) IE00B4L5YX21 SJPA
Japan MSCI Japan Large & Mid Standard MSCI Japan benchmark LU1781541252 LCJP
Japan FTSE Japan Large & Mid FTSE methodology for Japanese equities IE00BFMXYX26 VJPB
Japan Nikkei 225 Large 225 most traded Japanese stocks LU0839027447 XDJP
Japan MSCI Japan Screened Large & Mid Excludes controversial industries IE00BFNM3L97 SGJP
Japan Solactive Core Japan L&M Cap Large & Mid ESG exclusions, low-cost alternative IE00BFXR5T61 LGJG
Netherlands AEX Large 25 largest Dutch stocks IE00B0M62Y33 IAEX
Korea FTSE Korea 30/18 Capped Large & Mid Broad Korea benchmark with 30/18 caps IE00BHZRR030 FLRK
Korea MSCI Korea 20/35 Large & Mid Korea benchmark with 20/35 caps IE00B3Z0X395 HKOR
Spain IBEX 35 Large 35 largest Spanish companies FR0010655746 CS1
Sweden OMX Stockholm Benchmark Cap Large & Mid Swedish equities with 5%/40% caps IE00BD3RYZ16 OMXS
Switzerland MSCI Switzerland Large & Mid Standard benchmark for Swiss equities LU1681044993 CSWG
UK FTSE 100 Large 100 largest UK stocks IE00B53HP851 CUKX
UK FTSE 250 Mid 250 UK mid-cap stocks IE00BFMXVQ44 VMIG
UK MSCI UK Large & Mid MSCI benchmark for UK equities LU0950670850 UC64
UK Morningstar UK Large & Mid Morningstar methodology for UK LU1781541096 LCUK
UK Solactive Core UK L&M Cap Large & Mid ESG exclusions, low-cost UK benchmark IE00BFXR5R48 LGUK
UK FTSE All-Share Large, Mid & Small Broadest UK equity benchmark IE00B7452L46 FTAL
USA S&P 500 Large 500 leading US stocks (blue-chip) IE00B5BMR087 CSP1
USA Nasdaq 100 Large (non-financial) US tech/growth tilt IE00BMFKG444 XNAQ
USA MSCI USA Large & Mid MSCI methodology for US equities IE00B60SX170 MXUS
USA Dow Jones Industrial Average Large 30 large industrial stocks (historic blue-chip) IE00B53L4350 CIND

Bonds

Unlike equities, where geography defines a clean hierarchy, fixed income exposures are multi-dimensional. To construct a usable hierarchy, we treat credit/issuer type as the dominant split, then subdivide by region and currency of issuance, and only where necessary by maturity. This tree captures the major correlation breaks while avoiding an unmanageable tensor of exposures.

Aggregate (Gov + Corp)

Level Region Index ETF ISIN Notes
Aggregate Global Bloomberg Global Aggregate Float Adjusted & Scaled (GBP Hedged) IE00BG47K971 Gov + Corp, IG only, all maturities, GBP hedged

Government Bonds

Level Region Index ETF ISIN Notes
Gov Global Bloomberg Global Aggregate Treasuries (GBP Hedged) IE000S6ZDHA0 Local currency, IG, GBP hedged
Gov Global Solactive Paris Aware Global Government (GBP Hedged) IE000QVCP9S5 Climate-aligned, IG, GBP hedged
Gov Eurozone Bloomberg Euro Treasury Bond IE00B4WXJJ64 Euro sovereigns, IG
Gov Eurozone Solactive Eurozone Government Bond LU1931975152 Euro sovereigns, IG
Gov US Bloomberg Global Agg US Treasury Float Adj IE00BGYWFS63 US Treasuries, float-adjusted
Gov UK FTSE Actuaries UK Conventional Gilts All Stocks IE00B1FZSB30 UK gilts, conventional only
Gov China Bloomberg China Treasury + Policy Bank (GBP Hedged) IE00BMZ17Y47 CIBM, sovereign + policy banks, GBP hedged
Gov EM JP Morgan EMBI Global Diversified 10% Cap 1% Floor IE00B5M4WH52 EM sovereigns, mixed ratings
Gov EM Bloomberg EM USD Sovereign + Quasi-Sov IE00BGYWCB81 USD-denominated, EM gov + semi-public
Gov EM Bloomberg EM USD Sovereign & Agency 3% Cap LU1324516050 USD-denominated, capped country exposure

Corporate Bonds

Level Region Index ETF ISIN Notes
Corp EM JP Morgan CEMBI Broad Diversified Core IE00BFM6TD65 EM corporates, USD, mixed ratings
Corp Eurozone Bloomberg MSCI Euro Area Liquid Corporates Sustainable LU1484799769 ESG-screened, IG
Corp Eurozone Bloomberg Liquidity Screened Euro HY Bond IE00B6YX5M31 HY, 1–15 yr maturity
Corp US Bloomberg SASB US Corp ESG Ex-Controversies IE00BLF7VX27 ESG-screened, IG
Corp US Bloomberg US Liquid Corporates (GBP Hedged) LU1048317298 Large/liquid, IG, GBP hedged
Corp UK Bloomberg Sterling Corporate Bond IE00B4694Z11 Sterling-denominated, IG

Inflation-Linked Bonds

Level Region Index ETF ISIN Notes
Infl-Linked Global Bloomberg World Gov Inflation-Linked (GBP Hedged) IE00BMDBML89 Developed gov, inflation-linked, GBP hedged
Infl-Linked US Bloomberg US Gov Inflation-Linked (GBP Hedged) IE00BDZVH859 TIPS, GBP hedged
Infl-Linked Eurozone Bloomberg Euro Gov Inflation-Linked IE00B0M62X26 Eurozone sovereign ILBs

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