How shares & investing work

This is the part that trips everyone up. Read it once and the whole product clicks.

"BUY SHARES" gives you shares, not tokens

When you deposit ETH into a vault, you don't directly own the basket tokens. You receive shares of the vault (an ERC-4626 token). Those shares are a claim on a slice of the entire vault — every token it holds plus any un-invested WETH, pooled together.

your value = (your shares ÷ total shares) × total vault value

You never own "your specific tokens." You own a percentage of the whole pot. This matters for everything below.

Depositing is two steps

A deposit actually does two distinct things on-chain:

Step	What it does	Who can trigger it
1. Deposit	ETH → WETH enters the vault, you get shares	Anyone
2. Invest	WETH gets swapped into the basket tokens	Creator / keeper only

Step 2 is separate because the swap needs an off-chain-computed route (which DEX, which pool, what calldata) — the contract can't figure that out by itself. So a wallet that's allowed to submit the route has to fire it.

When the creator deposits, the BUY SHARES button chains both steps in one flow — deposit + invest. Funds land in the basket immediately.

When anyone else deposits, only step 1 runs. Their WETH sits in the vault as an idle float until the creator (or the keeper) runs the invest step.

Idle WETH — what it costs you

Idle WETH isn't lost. It still counts toward the vault's value and your withdraw amount. But it's dead weight: it doesn't move when the basket tokens move.

Example — vault holds 0.05 ETH in tokens + 0.02 ETH idle WETH:

tokens +10%  →  0.05 → 0.055
idle WETH    →  0.02 → 0.02  (flat)
total        →  0.07 → 0.075  = +7.1%  (not +10%)

Everyone's shares only gain the blended +7.1%, because ~29% of the vault was sitting in cash. Investing the idle WETH restores full token exposure.

Because shares are a claim on the whole pool, you ride the vault's performance proportional to your shares — up AND down.

Vault: creator put 1 ETH (in tokens), a second wallet deposited 1 ETH. Each owns 50%.

Scenario	Tokens	Each holder's 50%
Tokens ×2	1 → 2 ETH (+WETH 1) = 3 ETH	1.5 ETH each (+50%)
Tokens → 0	0 (+WETH 1) = 1 ETH	0.5 ETH each (−50%)

Key takeaways:

A depositor with idle WETH still gains and loses with the vault — they're not "safely holding their ETH." Their shares are exposed to the whole pool.
Idle WETH dilutes the creator: their fully-invested position shares its upside with the idle deposit. The fix is to keep deposits invested (below) — then everyone has equal token exposure and nobody is diluted.

INVEST vs MANAGE BASKET

Two distinct creator actions on the vault page:

Button	Use it to	What it does
INVEST	deploy idle WETH as-is	swaps the WETH float into the basket at current weights, one flow
MANAGE BASKET	change weights / add / remove tokens	full rebalance — sells over-weighted, buys under-weighted

If a non-creator deposited and their WETH is sitting idle, the creator just clicks INVEST to deploy it. No weight change needed.

The INVEST button only shows to the creator and only when there's a non-dust WETH float to deploy.

Why the creator wants deposits invested

The creator earns fees on volume (see Creator economics) and holds their own appreciating position. Idle WETH hurts both: it drags the vault's performance down (less attractive → less volume → less fee revenue) and dilutes the creator's own returns. So it's always in the creator's interest to keep deposits invested promptly — which is why the protocol auto-wires this where it can.