How "if they sell, price drops X%" is calculated

Every Whodl coin page carries a line like "if the top 10 sell: about -62%". It turns the two numbers people stare at separately, concentration and liquidity, into the one they actually care about. This guide shows the math so you can check it.

The model

Most Solana pools, and the pools coins migrate into from launchpads, are constant-product markets: the pool holds some amount of the token (x) and some amount of SOL (y), and trades keep x × y constant. Selling tokens into the pool adds to x and removes from y, which lowers the price.

For a seller dumping Δx tokens into a pool with reserves x and y:

1. New token reserve: x + Δx
2. New SOL reserve: y × x ÷ (x + Δx)
3. New price: (new SOL reserve) ÷ (new token reserve)
4. Impact: new price ÷ old price − 1

Whodl reads the main pool's actual reserves at scan time, takes the group's combined balance as Δx, and reports the impact. It models the group selling everything at once, which is the worst case, and it ignores fees (which make it slightly worse) and other buyers stepping in (which make it better).

A worked example

A coin with 1 billion supply, a pool holding 200 million tokens and 400 SOL, so the price is 0.000002 SOL per token and the pool is worth about 800 SOL in total.

The top 10 wallets hold 300 million tokens (30% of supply). If they sold everything:

• New token reserve: 200M + 300M = 500M
• New SOL reserve: 400 × 200M ÷ 500M = 160 SOL
• New price: 160 ÷ 500M = 0.00000032 SOL
• Impact: 0.00000032 ÷ 0.000002 − 1 = −84%

Notice that the top 10 received only 240 SOL for tokens "worth" 600 SOL at the old price. That gap is why large holders cannot exit at the number on the screen, and why the first seller out does best.

The groups Whodl models

• Top 10 wallets, pools and exchanges excluded.
• The biggest wallet alone.
• The biggest linked group from the bubble map, which is the realistic "one decision" seller.
• The week's sellers: wallets that already sold this week, modelled selling the rest.
• The dev and its linked wallets.

Across the coins Whodl has checked

Among the 7 coins with the model, the median impact of the top 10 selling is 86.7%, and on 100% of coins it is more than 50%. On 42.9% of coins the top 10 hold more value than the whole pool. See how much liquidity is enough.

What the number does not say

• It does not say the group will sell. It says what happens if they do.
• It assumes one pool. Coins with several pools get the main one; the page lists the others.
• It ignores bonding-curve pricing before migration, where the launchpad's own curve applies.
• It does not model buyers absorbing the sell, which is the only thing that makes the real outcome better than the model.

Check the impact line, the pool reserves and the group balances on any coin under coin reports.