In general, cryptocurrency arbitrage begins when you buy a cryptocurrency on one of the exchanges. Before the purchase, the risk is basically limited only to the costs of preparing such a transaction, that is, for example, sending the funds to a given exchange. These will not be large costs, but you should know that they can also occur.

From the moment of purchase, all activities basically come down to the same thing - selling the purchased cryptocurrencies at a higher price. Along the way, several events can occur that will make this impossible or much more difficult.

The first problem with typical arbitrage is the time to transfer funds from one exchange to another. Normally, the operation itself should take from a few to several dozen minutes. After this time, it may turn out that the price on the target exchange has already fallen, and the whole opportunity is already outdated. The time to transfer a cryptocurrency consists of three stages:

"Clicking" the transfer order and confirming it - to do this, you need to check the deposit address on the destination exchange. This involves logging into it and often a two-step authentication. Then you have to enter all the data and usually confirm the withdrawal by clicking on the link sent by email.
Waiting for the transfer to be approved by the source exchange - this should not take more than a few minutes. There can sometimes be downtime at this stage, especially when multiple users suddenly want to transfer the same cryptocurrency.
Cryptocurrency transfer time over the network - each exchange requires a certain number of transaction confirmations from the network for a given cryptocurrency. So after a block with your transaction has occurred in the blockchain, you still have to wait for a certain number of more blocks to occur. You can track all this in the blockchain by having a transaction ID, which is usually provided by the source exchange after the transfer. The largest portion of cryptocurrencies are based on the ERC20 protocol, where it takes a few to several minutes to get the number of 30 confirmations.
Therefore, in most cases, the time of sending cryptocurrencies to another exchange is predictable. Each time you need to calculate the risk that once the funds are booked on the other exchange, the sales opportunity will no longer be valid.

Crypto arbitrage