TVL is DeFi's headline metric and its most misleading one. Double counting, price effects and mercenary capital all inflate it. Here is how to read it properly and what to look at instead.

Total Value Locked is the number every DeFi protocol leads with. It is also the number most likely to mislead you, because it measures something subtly different from what people assume.
TVL is the current market value of assets sitting in a protocol's contracts. That is all. It is not revenue, not users, and not a measure of quality.
If a protocol holds 1,000 ETH and ETH doubles, TVL doubles. Not one new user arrived and not one extra deposit was made.
This runs both ways and explains most dramatic TVL charts. A protocol whose TVL fell 60% in a drawdown may have lost no deposits at all. Denominating in the underlying asset rather than dollars tells you far more about whether people are actually leaving.
This is the big one, and it follows directly from composability.
Stake SUI, get a liquid staking token — the staking protocol counts it. Supply that token to a lending market — the lending market counts it too. Borrow against it and supply the proceeds to a pool — counted a third time.
One deposit, three protocols' TVL. Aggregators try to net this out, but methodologies differ and protocols have every incentive to report the flattering figure.
Capital chasing an incentive programme is counted identically to capital that has sat for two years. When emissions taper, the first kind leaves within days.
This is why TVL can collapse without anything breaking. The yield stopped, so the mercenary capital moved on — exactly as designed. See how protocols make money for why emissions-funded deposits behave this way.
It is not useless — it is just narrower than advertised.
For a lending market, TVL is available borrowing capacity, which is real. For a DEX, it is depth, which determines slippage on large trades. For anything where you need to exit at size, TVL tells you whether you can.
The rule: TVL is useful as a measure of capacity, misleading as a measure of quality.
Higher TVL means a larger prize for an attacker. It also usually means more audits and more scrutiny. These roughly offset, so TVL is a weak security signal in either direction.
What matters more is time. A protocol holding meaningful value for two years without incident has demonstrated something no audit can. See proof of reserves for verifying that assets are actually there.
When you see a TVL figure, ask three questions.
Applied to comparisons — our Sui DeFi platforms and Sui liquid staking guides both quote TVL, and both are better read alongside these questions than as league tables.