The Woodford Equity Income fund froze in 2019 and trapped hundreds of thousands of investors because it held stakes in tiny, hard-to-sell companies. Six years on, campaigners are still demanding a public inquiry, arguing the industry never truly learned the lesson about illiquid holdings. This guide shows you how to spot liquidity risk and dangerous concentration in your own portfolio, and how to set diversification alerts before a position becomes a trap.
What actually went wrong with the Woodford fund?
The Woodford Equity Income fund collapsed because it packed a supposedly liquid, open-ended fund with illiquid holdings that could not be sold quickly enough to meet redemptions. When investors rushed for the exit in 2019, the manager could not raise cash without dumping large stakes at fire-sale prices.
At its peak the fund managed roughly 10 billion pounds. By the time it was suspended in June 2019, it had shrunk to around 3.7 billion pounds, and investors were locked in while assets were wound down at a loss.
The core problem was a mismatch between two things:
- Daily liquidity promised to investors who could ask for their money back any day the market was open.
- Illiquid underlying assets, including unquoted startups and thinly traded small-caps that could take weeks or months to sell.
On August 28, campaigners renewed calls for a public inquiry, arguing that few structural lessons have been learned. You cannot fix industry rules yourself, but you absolutely can audit your own portfolio for the same trap.
What is liquidity risk, in plain terms?
Liquidity risk is the risk that you cannot sell an asset quickly at a fair price when you need to. An asset is liquid when there are always ready buyers, and illiquid when selling forces you to accept a discount or wait.
Liquidity sits on a spectrum. Here is how common holdings compare:
| Asset type | Typical liquidity | Time to exit at fair price |
|---|---|---|
| Large-cap stocks (AAPL, MSFT) | Very high | Seconds |
| Major crypto (BTC-USD, ETH-USD) | High | Seconds to minutes |
| Small-cap or micro-cap stocks | Low | Days to weeks |
| Unlisted or private holdings | Very low | Months or longer |
The Woodford lesson is that liquidity is not a fixed property. A holding that looks tradeable in calm markets can freeze the moment everyone wants out at once.
How do you spot illiquid holdings you already own?
You spot illiquid holdings by checking three signals: daily trading volume, bid-ask spread, and market capitalisation. If a stock trades thin, has a wide spread, and sits below roughly 500 million in market cap, treat it as a liquidity flag.
The three checks that matter most
- Average daily volume. Compare your position size to the stock's average daily traded value. If your holding is more than 1 to 2 percent of a normal day's volume, exiting will move the price against you.
- Bid-ask spread. A large-cap like MSFT trades at a spread of a cent or two. A micro-cap can show spreads of 3 to 5 percent, and you pay that gap every time you trade.
- Listing status. Unlisted stakes, pre-IPO shares and some structured products have no continuous market at all.
The trickier danger is hidden illiquidity inside funds. An ETF or fund can look liquid on the surface while holding illiquid names underneath, exactly the Woodford structure. If you want to see what you really own, our guide on how much Apple you really own across your funds walks through the look-through process.
Why does concentration make illiquidity so much worse?
Concentration multiplies liquidity risk because a big position in a thin asset is exactly the combination that traps you. A 2 percent stake in a micro-cap is annoying to sell; a 20 percent stake can be impossible to sell without crashing the price.
Concentration hides in several places most investors never check:
- Single-name concentration. One stock quietly grows to 30 percent of your portfolio after a strong run.
- Sector concentration. Multiple holdings that all move together, like a cluster of semiconductor names.
- Overlap concentration. Two funds that both hold the same top-10 stocks, doubling your exposure.
Sector clustering is a real modern example. If you hold several chip and AI names, read our breakdown of the AI compute boom hiding in your portfolio's blind spots to see how correlated exposure sneaks in.
How do you measure concentration in your own portfolio?
You measure concentration by ranking every holding as a percentage of total portfolio value, then grouping those percentages by asset, sector, and geography. Any single line above 10 percent, or any sector above 25 percent, deserves a second look.
A simple concentration audit
- List each holding as a weight. Position value divided by total portfolio value.
- Group by sector and region. Add up weights so you see clusters, not just individual names.
- Flag anything oversized. Compare each weight against your own thresholds.
- Cross-check liquidity. For every oversized position, ask how many days it would take to exit.
Doing this in a spreadsheet is possible but painful to keep current, which is why many investors moved on from manual tracking. Our comparison of a portfolio tracker versus a spreadsheet covers where manual sheets break down for risk monitoring.
How does PortfolioTrackr help you catch this early?
PortfolioTrackr shows concentration and exposure across every holding in one place, then lets you set diversification alerts that fire the moment a position or sector crosses a level you choose. It reports status against your own thresholds; it does not tell you what to buy or sell.
Here is how the workflow looks:
- Aggregate everything. Track stocks across 95 stock exchanges, crypto, and UAE markets like the Abu Dhabi Securities Exchange and Dubai Financial Market side by side, in any of 67 currencies.
- See true weights. Each holding is shown as a percentage of your total, so a position quietly ballooning to 25 percent becomes obvious.
- Set your own thresholds. For example, alert me if any single stock passes 15 percent of the portfolio, or if one sector passes 30 percent.
- Get status, not advice. When a level is reached, PortfolioTrackr reports the status against your target so you can decide.
Connecting a broker is optional. You can add positions by manual entry, voice, text, CSV upload, or a broker screenshot on every plan. If you do want automatic syncing, PortfolioTrackr connects through the SnapTrade bridge to 35 brokers plus three direct integrations with Alpaca, Bybit, and Interactive Brokers. The full walkthrough is in our guide on how to connect your brokerage account to a portfolio tracker.
What about illiquid private and alternative assets?
Private and alternative assets carry the highest liquidity risk because there is often no daily market at all, so a freeze can last months or years. Private equity funds, venture stakes, and some property vehicles can gate redemptions exactly the way Woodford did.
Practical guardrails for anything hard to sell:
- Cap the illiquid sleeve. Decide in advance what percentage of your total wealth can sit in things you cannot exit quickly.
- Keep a liquidity buffer. Hold enough cash and large-cap positions to cover real needs without touching illiquid assets.
- Read the redemption terms. Notice periods, gating clauses, and lock-ups tell you how fast a fund can freeze.
We go deeper into this in our piece on spotting illiquidity risk when private assets freeze, which is the closest modern echo of the Woodford story.
The bottom line
The Woodford collapse was not caused by picking bad companies; it was caused by a mismatch between promised liquidity and illiquid holdings, made lethal by concentration. The same trap can form quietly in any portfolio when one position grows too large or one asset turns out to be thinner than it looked.
Protect yourself with a routine: audit weights, check liquidity, and set alerts before a position becomes a problem. PortfolioTrackr gives you the aggregated view and the diversification alerts to catch concentration and liquidity risk while you still have room to act on your own terms.
Find out what you are actually exposed to
Sector and currency concentration across every account you hold, benchmarked against the S&P 500, NASDAQ and gold.
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Frequently asked questions
Why did the Woodford Equity Income fund collapse?
The fund collapsed because it held illiquid assets, including unquoted startups and thinly traded small-caps, while promising investors daily redemptions. When redemption requests surged in 2019, the manager could not sell those holdings fast enough at fair prices, so the fund was suspended and later wound down at a loss.
How can I tell if a stock I own is illiquid?
Check three signals: average daily trading volume, the bid-ask spread, and market capitalisation. If your position is more than 1 to 2 percent of normal daily volume, the spread runs several percent, or the company sits below roughly 500 million in market cap, treat it as an illiquidity flag.
What is a safe level of concentration in a single stock?
There is no universal rule, but many investors treat any single holding above 10 percent of the portfolio as a review trigger, and above 20 percent as high risk. The right threshold depends on your goals, but concentration matters most when the oversized position is also illiquid.
Can PortfolioTrackr alert me when a holding gets too big?
Yes. PortfolioTrackr lets you set diversification alerts on any threshold you choose, such as a single stock passing 15 percent or a sector passing 30 percent. It reports status against your own levels the moment they are reached, showing you the situation without giving buy or sell advice.
How do I check if my funds secretly hold illiquid stocks?
Look through each fund to its underlying holdings rather than judging the fund by its own tradeability. A fund can trade daily while owning illiquid names beneath the surface, which was the core Woodford problem. Reviewing holding-level exposure across all your funds reveals hidden concentration and liquidity risk.