If you have any bitcoin stored at Coinbase or any other online exchange, it’s probably a good idea to move it into a private wallet that you control ASAP.

On August 1st, the Bitcoin network will likely fork into two separate blockchains—which will create a new currency in the process. Everyone that owns bitcoin will automatically receive an equivalent amount of the new currency, called “Bitcoin Cash” (BCC)—but this is only guaranteed to happen for you if you control the private key to the wallet address where your BTC is stored on August 1st. In other words, if you leave your BTC on an exchange during the fork, you’ll be at the mercy of the exchange as to whether or not they decide to give you the BCC that is created from the split.

Coinbase has already publicly stated that they’re taking the ethically questionable stance of not transferring the newly-created BCC to customers that trust them to hold their BTC during the fork. Other exchanges, such as Bittrex, have explicitly told their customers that they’ll be credited with whatever BCC their BTC generates. If you want the BCC that you’re entitled to, and have any doubt as to where your exchange stands, make sure that you transfer your BTC to your own private wallet at some point before Tuesday!

Given that the futures price for BCC is currently hovering around $400/coin, and many people expect it to end up somewhere between 10-20% of BTC’s value after the fork, there is potentially a lot of money at stake for people with sizable bitcoin holdings.