Liquidity bootstrapping pool (LBP)

A liquidity bootstrapping pool is a two-token automated market maker whose weights change on a schedule instead of staying fixed, typically starting heavily weighted toward the project token and shifting toward the reserve asset over a sale window of a few days. The descending weight applies continuous downward pressure on price, so a buyer who waits pays less than a buyer who rushes. Balancer is the reference implementation.

An LBP inverts the launch-day race. In a fixed-price pool the first transaction in the block wins, so bidding priority fees is rational; in an LBP the price falls on a clock, so waiting is rational. That single change is what the mechanism buys you, and it is the only thing it buys you.

Weights set the price, and the weights are on a timer

A standard weighted pool holds two assets at a fixed ratio, commonly 50/50 or 80/20, and price is a function of the reserves. An LBP uses the same weighted maths with time-dependent weights, so the pool owner sets a starting weight, an ending weight, a start time and an end time, and the weights move linearly between them.¹ Balancer's own example runs 90/10 project token to reserve token and shifts toward 10/80.¹

The access controls matter as much as the curve. Only the pool owner can add liquidity, and that has to happen before the sale opens. Proceeds can only be withdrawn after the end time. Swaps are enabled only between the start and end timestamps, and a boolean called blockProjectTokenSwapsIn lets the owner stop the project token being sold back into the pool, which is typically switched on for a launch.¹

Read that list as the centralisation disclosure it is. During the sale the owner is the only liquidity provider, can restrict which direction trades run, and holds the proceeds behind a time lock they configured. Buyers are trusting a configuration, not a market.

Why the descending curve resists sniping

Balancer describes the standard configuration as a continuous Dutch-auction-style mechanism: the scheduled reweighting creates controlled downward price pressure, which distributes tokens more broadly while reducing the incentive for bot sniping and whale concentration, because buyers can enter when the price reaches a level they consider fair rather than rushing into a priority-fee bidding race at launch.¹

The counterintuitive part is the starting price. Balancer's guidance is to treat the opening price as a ceiling and set it much higher than what you believe the fair price is, precisely so the weight shift has room to lower the price progressively until market equilibrium is reached. Unlike a bonding curve, users are disincentivised from buying early and benefit from waiting.² A high starting weight also produces high slippage on large orders, which is the same defence expressed a second way.³

This is where teams get the mechanism wrong. An LBP opened near the price you actually want is an LBP with no headroom, and it behaves like a fixed-price sale with extra steps. The whole defence lives in the distance between the opening price and the clearing price.

The first one, with its configuration published

Perpetual Protocol's PERP sale in September 2020 was the first Balancer LBP and remains the most completely documented. The pool shifted from 90/10 to 30/70 PERP to USDC, linearly across 20,080 blocks, which came to roughly 72.5 hours at an average 13 second block time. It opened with 7,500,000 PERP and 1,333,333 USDC, implying a starting price of $1.60, and the weight shift alone would have suppressed the price toward $0.08 in the absence of buying.³

That $1.60 to $0.08 span is the headroom the previous section is about. Delphi's contemporaneous analysis worked the other side of it: assuming $200,000 of USDC traded in the first hour while the pool was near 90/10, roughly $109,000 an hour would need to trade every hour afterwards to hold PERP at $1.60 through to expiry, totalling around $7.85 million of net USDC inflow.³ The pool tells you exactly what sustained demand costs.

Those figures describe one sale in 2020 and are cited as a configuration example, not as a benchmark for what any future sale should raise or clear at.

Scroll to see the full diagram

The falling bar is the sell pressure. Nobody has to trade for the price to drop, which is why a buyer gains nothing by being first and the priority-fee race never starts. Weights interpolated linearly from the published 90/10 to 30/70 schedule over 72.5 hours.

What a completed LBP looks like from the other side

Radicle ran its RAD distribution as a Balancer LBP and posted the closing numbers from its own account: over 1,800 new token holders, almost $25 million raised for the treasury, and roughly 1.875% of total supply claimed through the event, with swapping on Balancer paused at the close.⁴

The number to sit with is 1.875%. An LBP is a price discovery and treasury funding event over a slice of supply, not a distribution of the supply. The remaining 98% is still governed by your allocation table, your vesting contracts and your unlock schedule, and none of those are affected by how elegantly the sale went.

The 1,800 holders figure is the other honest signal. Broad distribution is the stated aim of the mechanism, and 1,800 addresses is a real outcome rather than a large one. Size the expectation accordingly.

What an LBP does not solve

It does not create demand. A descending price finds where demand already is, and if that level is far below what your round priced at, the LBP has told you something expensive and true rather than caused it.

It does not leave you with a market. When the end time passes, the owner withdraws the proceeds and the pool stops being a venue. Standing liquidity on a normal pool, and who funds it, is a separate decision that has to be made before the LBP closes, not after.

And it does not remove the owner powers described in the first section. A sale in which one party controls liquidity, direction and timing is a sale on terms, and the terms should be published with the schedule rather than discovered in the contract. Across the launches we have worked on, the projects that publish start weight, end weight, start time, end time, opening price and pool composition in advance get fewer questions afterwards, because there is nothing left to reconstruct.

Common questions

What is a liquidity bootstrapping pool?

It is a two-token automated market maker whose weights change on a schedule set by the pool owner rather than staying fixed. Balancer's weight-shifting LBPs use weighted maths with time-dependent weights, starting heavily weighted toward the project token, for example 90/10, and shifting toward the reserve asset over a defined window between a start and end timestamp.¹

How does an LBP stop bots and snipers?

By removing the reward for being first. The scheduled reweighting creates continuous downward price pressure, so a buyer can wait until the price reaches a level they consider fair instead of racing into a priority-fee bidding war at the open.¹ A deliberately high starting weight also produces heavy slippage on large early orders, which discourages whale concentration in the first blocks.³

Why does an LBP start at a high price?

So the weight shift has room to work. Balancer's guidance is to treat the opening price as a ceiling set well above what you believe the fair price is, letting the changing weights lower the price progressively until it reaches market equilibrium.² Opening near the target price removes the headroom, and the sale then behaves much like a fixed-price offering.

How much of a token supply is usually sold in an LBP?

A small slice. Radicle reported roughly 1.875% of total supply claimed through its LBP, alongside over 1,800 new holders and almost $25 million raised for the treasury.⁴ Treat an LBP as a price-discovery and treasury event over a narrow tranche, not as the mechanism that distributes your supply. The allocation table and vesting schedule still do that work.

See Token Launch Strategy for how this applies in practice.

Sources

Liquidity Bootstrapping Pools (LBPs)
Balancer, official documentation, 2026
Reference implementation. Read 3 August 2026: weight-shifting LBPs using weighted maths with time-dependent weights, the 90/10 to 10/80 example, the continuous Dutch-auction framing and anti-sniping rationale, and the pool settings including owner-only liquidity provision, the startTime and endTime window, post-end withdrawal of proceeds and the blockProjectTokenSwapsIn flag.
Liquidity Bootstrapping Pools (LBPs), docs source file
Balancer, official docs repository on GitHub, 2026
Source-controlled docs carrying the mental model section: treat the starting price as a ceiling set much higher than the believed fair price so the changing weights can lower price progressively to market equilibrium, with users disincentivised from buying early. Read 3 August 2026.
Get Ready for Balancer's First-Ever Liquidity Bootstrapping Pool ($PERP)
Delphi Digital, analyst Paul Burlage, 2020
Contemporaneous analysis of the first Balancer LBP, dated 5 September 2020, with the full configuration: 90/10 to 30/70 PERP/USDC linearly across 20,080 blocks, about 72.5 hours; 7,500,000 PERP and 1,333,333 USDC implying a $1.60 opening price; suppression toward $0.08 absent buying; and the roughly $7.85 million net USDC inflow modelled to hold $1.60.
The Radicle LBP event has ENDED (official account post)
Radicle, official X account, 2021
The project's own close-of-sale announcement, confirmed 3 August 2026: swapping on Balancer paused, over 1,800 new token holders, almost $25 million raised for the treasury and roughly 1.875% of total supply claimed.

Last reviewed 2026-08

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