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Venture Portfolios Are Built Around the Assumption That Most Die

The mathematics of venture require a small number of enormous outcomes to cover everything else. That single fact determines fund size, position count, and which companies get funded.

↩ Looking BackPart of the 2020 to 2026 retrospective, written in July 2026. The date below marks the 2024 events this piece revisits, not when it was published, so it draws on everything known through mid 2026.
Nathan Xiang·February 11, 2024

The Distribution

Venture returns are not normally distributed. They follow something closer to a power law, where a very small number of investments produce the overwhelming majority of returns.

A typical fund outcome has most investments returning little or nothing, a group returning capital or a small multiple, and one or two producing an extraordinary result that determines whether the fund succeeded.

This is not a failure of selection. It is the structure of the asset class, and every design decision follows from accepting it.

The objective is not to be right often. It is to be enormously right at least once, which requires being wrong many times without that being fatal.

What Follows for Position Count

If returns depend on catching an extreme outcome, and extreme outcomes are rare, the portfolio needs enough positions to have a reasonable chance of containing one.

Too few positions and the fund is a bet on specific companies in a category where prediction is genuinely difficult. Too many and the winner, when it arrives, is too small a share of the fund to move the result.

Different firms resolve this differently. Some run concentrated portfolios with deep involvement. Others run wide portfolios accepting that most receive little attention. Both are coherent responses to the same mathematics.

The Fund Size Constraint

Fund size determines what outcome is required, and this constraint is more binding than it appears.

Fund sizeNeeded for a 3x fundImplication
50 million150 million returnedModest exits can work
500 million1.5 billion returnedNeeds large outcomes
2 billion6 billion returnedOnly the largest exits matter

A large fund cannot be moved by a company that sells for 200 million dollars, regardless of the multiple achieved on that specific investment. This forces large funds toward companies with the potential for enormous outcomes, which changes what they will fund and at what stage.

It also explains why successful small fund managers who raise a much larger fund sometimes underperform. The strategy that worked at small scale does not produce results large enough to matter at large scale.

Reserves and Follow On

A substantial part of a venture fund is typically reserved for follow on investment in existing portfolio companies rather than for new positions.

The reasoning is that the fund has better information about its own companies than about new ones, and that pro rata rights allow it to maintain ownership in the winners as they raise larger rounds.

The discipline is in deciding which companies deserve reserves. Following into companies because they need money rather than because they are working converts reserves into a mechanism for increasing exposure to failures. Following into the winners is where reserves earn their keep, and identifying which is which in real time is the actual skill.

Why Ownership Percentage Drives Behaviour

Because returns depend on a small number of outcomes, the percentage owned in those specific companies determines the fund result.

This is why venture firms care intensely about initial ownership targets and about maintaining them through subsequent rounds. A 15 percent stake in a company that returns the fund is a different outcome from a 3 percent stake in the same company.

It also explains competitive behaviour around allocation, board seats, and pro rata rights, all of which look like status concerns and are mostly arithmetic.

The Consequence for Founders

Understanding the fund mathematics explains investor behaviour that otherwise seems irrational. An investor pushing a company toward a riskier, larger opportunity rather than a reliable modest one is following the incentive their portfolio creates.

A company that would be an excellent outcome for its founders may be irrelevant to a large fund, and the advice given will reflect that. It is not bad faith, and it is a genuine misalignment worth recognising before accepting the money.

The Bottom Line

Venture portfolio construction assumes a power law where one or two investments produce most of the return. Position count must be high enough to catch an extreme outcome, fund size determines what outcome is large enough to matter, and reserves exist to increase ownership in whichever companies are working. The same mathematics explains why large funds push for enormous outcomes even when a smaller one would suit the founders perfectly well.

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