Pump fun bundler: how bundled launches work on chain

The short answer

A pump.fun bundler creates your coin and buys it from several wallets you control in the same block by sending all the transactions to Jito as one bundle. The first transaction creates the coin and makes your dev buy; up to four more carry buys from your other wallets, about 16 buyers in total. The bundle lands in one slot, in order, or not at all. Every bundled buy is still a public first-block purchase that screeners flag.

Why do people bundle a pump.fun launch?

People bundle a launch so their own wallets get the launch price without anyone else buying in between. On a normal launch, the create transaction lands, and the creator's other wallets then race the public, including server-side sniper bots that buy in the same block. Each outside buy moves the curve, so a creator who wanted to split a team allocation across several wallets ends up paying more for each one.

A bundle removes the race. Because Jito runs the bundle's transactions back to back in one slot, the price of every buy is known before you sign. The legitimate reasons to want that are buying for your own team, treasury or marketing wallets at the launch price, and doing it in the open.

How does a pump.fun bundler work on chain?

A pump.fun bundler works by filling one Jito bundle with a create and a sequence of buys. Jito's bundle documentation sets the rules: at most 5 transactions, executed in the order listed, in the same slot, and only if every transaction succeeds.

Here is how SOLTidy's Pump.fun Bundle Launcher lays a bundle out:

Transaction	Signed by	Contents
1	Your connected wallet and the new mint	pump.fun create_v2, your dev buy, the tool fee
2	Buyer wallets 1–4	4 buys, each opening its own token account
3	Buyer wallets 5–8	4 buys
4	Buyer wallets 9–12	4 buys
5	Buyer wallets 13–15	3 buys plus the Jito tip

The limit of about four buys per transaction comes from Solana itself: legacy and v0 transactions are capped at 1,232 bytes, according to the Solana transaction docs, and every buyer adds a 64-byte signature, its accounts and its instructions. Five transactions with that packing give 16 buyers including you. Other launchpads pack differently: a Bonk.fun buy also wraps SOL, so only two fit per transaction and a Bonk.fun bundle holds nine buyers.

The create itself is pump.fun's own instruction. pump.fun's coin creation docs describe a Token-2022 mint with 6 decimals, and an instruction pair that "returns the create_v2 instruction followed by a buy_v2 instruction so the creator can seed the curve in a single transaction." The program fixes the supply at 1 billion tokens and keeps no mint or freeze authority.

How the buys are priced

Each buy moves the bonding curve, so the bundler quotes the wallets one after another on the curve the earlier buys leave behind. Every buy carries a maximum cost from your slippage setting. If anything changed, a buy that would exceed its cap fails, and Jito drops the whole bundle rather than let it land half-filled. What is a Jito bundle covers tips and failure modes.

How much of the supply does a bundle take?

A bundle takes more supply than most people expect, because the curve is cheapest at the start. These figures are calculated from pump.fun's published curve parameters (30 virtual SOL, 1.073 billion virtual tokens) with the 1.25% fee taken out of each buy:

Total SOL bundled into a fresh curve	Tokens bought	Share of 1B supply
1 SOL	≈ 34.2M	≈ 3.4%
2 SOL	≈ 66.3M	≈ 6.6%
4 SOL	≈ 124.8M	≈ 12.5%
8.5 SOL (1 SOL dev + 15 × 0.5 SOL)	≈ 234.6M	≈ 23.5%
16 SOL	≈ 370.2M	≈ 37.0%
31 SOL	≈ 541.9M	≈ 54.2%

A bundle of 8.5 SOL leaves the creator's wallets holding nearly a quarter of the supply before anyone else has bought. Traders read that number. Many avoid coins where bundled wallets hold more than a small share, because those wallets can sell into later buyers at any time. The SOLTidy tool shows the bundled share before you launch so you can decide whether the number is one you would want to defend in public.

What does a pump.fun bundle launch cost?

A bundle launch costs the buys themselves, pump.fun's trading fee inside them, account rent per buyer, the Jito tip and the tool's fee. pump.fun charges nothing to create a coin.

Item	Who pays	Amount
Dev buy and buyer-wallet buys	Each wallet	What you set (pump.fun's 1.25% fee included)
Token account rent	Each buyer	≈ 0.0015–0.002 SOL
Jito tip	First wallet of the last transaction	0.001 SOL by default
SOLTidy fee	Your wallet, inside the create	0.3 SOL per bundle
Network fees	Each transaction	A few thousandths of a SOL

Example: a 1 SOL dev buy and 15 wallets buying 0.5 SOL each spend 8.5 SOL on tokens, about 0.03 SOL on token accounts, 0.001 SOL on the tip and 0.3 SOL to SOLTidy, roughly 8.83 SOL in all. Because the fee is inside the create transaction, it is only charged if the bundle lands. Fund the buyer wallets first; the Solana Wallet Manager keeps them in encrypted groups and funds them for 0.0009 SOL per wallet.

Prices and wallet counts differ between bundlers. Pump.fun bundlers compared puts Smithii, Slerf Tools and SOLTidy side by side, dated, including where the others are cheaper.

How are private keys handled?

Each buyer wallet has to sign its own buy, so a bundler needs those wallets' keys. That is the biggest risk in the whole process, and tools differ in how they handle it. On SOLTidy the keys you paste are parsed and used to sign only in your browser tab, never sent to SOLTidy or stored, and wiped after signing, when you clear the field and when you leave the page. Your main wallet signs the create transaction without sending it, and only the fully signed transactions go to Jito.

Whatever tool you use, generate fresh wallets for the launch and fund them with only what they will spend. Never paste the key of a wallet that holds savings.

What can go wrong with a bundle launch?

Most problems are technical and cost nothing, because a failed bundle never executes:

• The bundle doesn't land. The tip was too low for a busy slot, a buy exceeded its slippage cap, or approval took longer than about a minute and the blockhash expired. Nothing happens on chain; SOLTidy keeps the same coin address so a retry can never create a second coin.
• No Jito leader. Bundles only land in slots whose leader runs Jito's client. Most stake does, but a bundle can wait a few slots.
• The market reacts. Once the coin is live, bundled supply is visible within seconds. If buyers don't come, the bundled wallets hold tokens that can only be sold back into the curve at a loss.

Selling later works like buying: each wallet sells its own tokens. Pump.fun Mass Sell sells from up to 200 wallets on the curve or on PumpSwap after graduation, for 0.5% of the SOL received, capped at 0.1 SOL per run.

Is bundled supply hidden?

No, and it should not be presented as if it were. Every bundled wallet buys in the coin's first block. pump.fun's holder list, Solscan and screeners such as RugCheck, Bubblemaps and GMGN show which wallets bought at launch and how much they hold, and label it as bundled. Funding trails link the wallets back to whoever funded them.

Use bundling honestly: disclose the team wallets, keep their share reasonable and don't sell into buyers who don't know about them. Don't use it to fake demand or to make a coin look more widely held than it is. That misleads buyers, and in many places it can break market manipulation and consumer protection laws. Before launching, the free rug check shows how your coin will look to a cautious buyer.

Bottom line

A pump.fun bundler puts the create, your dev buy and up to 15 other wallets' buys into one Jito bundle that lands in one block or not at all. It guarantees order and price for your own wallets; it does not hide them. Expect 8.5 SOL of bundled buys to take about 23.5% of supply, budget 0.3 SOL plus a tip on SOLTidy, keep buyer keys in fresh wallets, and disclose what you bundled. For a launch without bundling, the pump.fun token launcher makes the dev buy in the create transaction for 0.1 SOL.