The pump.fun curve, step by step
Every pump.fun coin is minted with 1,000,000,000 tokens and 6 decimals, and starts life on a bonding curve that prices it from virtual SOL and token reserves (x times y stays constant). A buy removes tokens and adds SOL, so the next buyer pays a slightly higher price. Twenty wallets buying back to back therefore climb the curve: the twentieth fills well above the first.
The review simulates that climb before anything is signed. It takes the live reserves, applies each planned buy in order to a copy of the curve and reports the tokens every wallet should get and the price impact of the whole run. At send time the curve is read again (at most every 1.5 seconds), so each wallet's minimum-tokens floor matches the price it actually meets.
buy_exact_sol_in: spend exactly what you set
The instruction each wallet signs is pump.fun's buy_exact_sol_in, built with pump.fun's own SDK. It spends the exact SOL amount you chose, with pump.fun's fee taken out of that amount rather than added on top, and it reverts if the tokens received would fall below your slippage floor. That makes per-wallet spending predictable even when other traders are hitting the same curve.
A wallet buying pump.fun for the first time also creates pump.fun's per-user volume account, and a wallet new to this coin opens its token account. Both are rent, not fees, and the planner reserves SOL for them so no wallet fails halfway.
Graduation to PumpSwap mid-run
When the last curve tokens are bought, the curve is marked complete and pump.fun migrates the liquidity to PumpSwap, its own AMM. A curve buy sent after that point is rejected in simulation, before any SOL moves. The run then re-reads the coin, sees it has graduated and sends the remaining wallets through Jupiter restricted to PumpSwap pools only, so no other DEX is touched.
Cost of a pump.fun run
pump.fun's fee depends on the coin's market cap; for a young coin it was 1.25% in November 2026 (0.95% protocol, 0.30% to the creator), and the page shows the live rate when you load the coin. SOLTidy's fee is 0.5% of the SOL spent, with a ceiling of 0.1 SOL for the entire run. The ceiling is reached at 20 SOL of buys; anything above that carries no SOLTidy fee at all.
Example: 60 wallets each spending 0.5 SOL put 30 SOL into the curve. At 0.5% that would be 0.15 SOL, but the run is capped, so SOLTidy receives 0.1 SOL in total and the last wallets' transactions contain no fee transfer. Sixty new token accounts add roughly 0.09 SOL of refundable rent.
| Item | SOL |
|---|---|
| Spent on the curve (pump.fun fee inside) | 30 |
| SOLTidy fee (0.5% = 0.15, capped per run) | 0.1 |
| Token account rent, first buy of the coin | ≈ 0.09 |
| Network fees at Fast priority | ≈ 0.001–0.02 |
Questions & answers
What does a pump.fun mass buy cost in fees?
pump.fun's trading fee for the coin's tier, inside the SOL you spend, plus SOLTidy's 0.5% of SOL spent, never above 0.1 SOL per run in total, plus each wallet's network fee and any first-time rent.
Why do the last wallets get fewer tokens?
Each buy moves the curve price up. The review shows the run's combined price impact; staggering the wallets or lowering the per-wallet amount softens it.
Can it buy a coin that already graduated?
Yes. A graduated coin is bought on PumpSwap through Jupiter, with every other venue filtered out.
What about Mayhem mode coins?
Those pay pump.fun's fee to a separate set of recipients. The tool reads the coin's mode from its curve and builds the buy with the right accounts.
What if a wallet's buy fails?
Every trade is simulated first, so a wallet short on SOL or past its slippage stops before paying anything, and the rest of the run continues. A buy whose blockhash expires is rebuilt and sent once more.
