Once you have an open position, tap Adjust (Mobile) or use the position row's actions (Web/Extension) to choose from:
Increase position
What it does: Adds more USDC as collateral and increases your position size, at your current leverage.
Funded the same way as opening a position — from wallet USDC or your Perps balance, in one signed transaction.
When to use it: You want more exposure to the same view, at the same risk profile (leverage) you already chose. Use this when your thesis hasn't changed — you just want to size up.
Example: You opened a 3x long on SOL with 100 USDC. Over the next few days, SOL trends the way you expected, and you're now more confident in the move. Rather than closing and reopening a bigger position you tap Increase and add another 50 USDC. Your position simply gets bigger, at the same 3x leverage, with a blended entry price.
Add collateral
What it does: Adds USDC to your position's collateral without changing its size.
Leverage drops.
Liquidation price moves further away from the current price (lower risk).
When to use it: You want to lower your risk of liquidation on a position you still believe in, without adding any more market exposure. This is the tool for "I want more breathing room," not "I want a bigger bet."
Example: You opened a 5x short on ETH, but the price has crept up closer to your liquidation price and you don't want to be stopped out on short-term noise before your thesis plays out. You tap Add collateral and commit another 40 USDC. Your position size doesn't change, but your leverage drops and your liquidation price moves further away — giving the trade more room to breathe.
Reduce collateral
What it does: Removes USDC from your position's collateral without changing its size.
Leverage rises.
Liquidation price moves closer to the current price (higher risk).
Removed collateral lands in your Perps balance — not your wallet. You'll need to withdraw separately (see article How to Withdraw).
When to use it: You want to free up USDC that's sitting idle as excess collateral on a position that's currently well clear of liquidation, for example, to redeploy it into a new position without touching your existing position's size.
Example: You opened a 2x long on BTC with 200 USDC, and the price has since moved strongly in your favor. Your liquidation price is now far from the current price, so some of that collateral is doing very little for you. You use Reduce collateral to pull 60 USDC back out. Your BTC position stays open at the same size, just at slightly higher leverage, and the 60 USDC becomes available in your Perps balance to fund a new trade (or to withdraw).
Warning: Reducing collateral moves your liquidation price closer to the market price. Only reduce collateral you're comfortable no longer having as a buffer on that position.
Close position
What it does: Closes all or part of your position.
Opens prefilled to a full close — reduce the amount for a partial close.
A partial close reduces your position size and collateral proportionally; your remaining position keeps the same leverage.
Proceeds (collateral plus/minus realized PnL, minus fees) settle to your Perps balance, not directly to your wallet.
When to use it: You want to lock in profit or loss, either on the whole position (full close) or on part of it (partial close) — for example, to take some profit off the table while letting the rest ride.
Example -> full close: Your 5x short on SOL hit your price target. You open Close, leave it prefilled to Max, and confirm. The full position closes, and your original collateral plus realized profit (minus fees) lands in your Perps balance, ready to withdraw or reuse.
Example -> partial close: You opened a 3x long on SOL and it's up significantly. You're not ready to exit entirely, but you want to bank some gains and reduce your exposure in case of a pullback. You open Close, change the amount from Max to 50% of your position, and confirm. Half your position closes and settles to your Perps balance; the remaining half stays open at the same leverage, still tracking the market.
Important: Whether you Increase, Add/Reduce collateral, or Close, the funds involved always move between your wallet and your Perps balance on Phoenix — never automatically both ways. See the article What Happened to My Perp Deposit? (Understanding Your Perps Balance) to understand where your money is at each step.