Question 1

How does the pump.fun bonding curve work?

Accepted Answer

Every pump.fun token launches on a constant-product bonding curve seeded with virtual reserves of about 30 SOL and roughly 1.073 billion tokens, so the product of the two reserves stays constant. Buying pushes SOL into the curve and pulls tokens out, and because price equals the SOL reserve divided by the token reserve, the price rises with the square of the SOL raised. The token graduates to a Raydium pool once around 85 real SOL have entered the curve — about a 69,000 dollar market cap at typical SOL prices — at which point the remaining tokens and liquidity migrate to the open market. This calculator reproduces that exact curve to price your entry.

Question 2

How many tokens do I get for my buy?

Accepted Answer

It depends where on the curve you buy. Because the curve is a constant product, the tokens you receive equal the curve constant times your effective SOL divided by the product of the SOL reserve before and after your buy — the same slippage math as any automated market maker. Buying early, when the reserve is small, gives you far more tokens per SOL and a much larger share of the fixed 1-billion supply than buying near graduation. The calculator shows your token count, your percentage of total supply, and the average price you actually paid after the 1 percent trade fee, which is always a little above the quoted market-cap price because your own buy moves the curve.

Question 3

Why is the expected value usually negative?

Accepted Answer

Because only about 1 to 2 percent of pump.fun launches ever graduate to Raydium, and most of the rest go effectively to zero. Your gross multiple if a coin reaches your target market cap can look huge, but the honest number is the odds-weighted expected value: the graduation probability times the winning multiple, with the losing branch worth nothing. At a 1.4 percent graduation rate you need a winner to return more than about 70 times your stake just to break even across many attempts. This calculator prints both the headline multiple and the break-even graduation odds so you can see whether the trade has positive expectancy or is a lottery ticket.

Question 4

Does buying earlier on the curve guarantee a profit?

Accepted Answer

No. Earlier entries get more tokens per SOL and a bigger supply share, so they need a smaller move to profit and pay off far more if the coin runs — but they are also exposed to the roughly 98 percent of launches that never graduate and collapse. Being early improves the payoff on the winners without changing the base rate of failures, so position sizing matters more than entry timing. Treat every memecoin buy as capital you can lose entirely, size it accordingly, and use the expected-value output here rather than the headline multiple to decide.

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