For cryptocoins it's nearly impossible. Because in most cases there's no idea when the actual transfer will be executed (if arbitraging between exchanges).
Concretely, imagine if every ten minutes you made an arbitrage buy on GDAX, and sell on BitFinex. As long as GDAX remains the “buy side” of the arbitrage, you will need to keep refilling your fiat funds at GDAX. You could “keep it filled,” but this becomes more unsustainable as you deplete your bankroll. You will eventually need to rebalance which will affect your velocity.
Disclaimer: I am not a financial professional.
Source: I tried to make money arbitraging BTC back in 2015. I made a 2x return, entirely because of inflation, realized I didn't understand anything I was doing and pulled my 8k out. If only I had kept it in :)
However, all the same risks apply e.g. with orders not being processed enough.
When you look at the price history (and open orders history) between some pairs on one exchange you'll find that during these spikes there was no arbitrage being done at all.
One example is seeing the price on ETH-BTC pair being constant despite BTC dropping 10-20%, and then combing back in 5-10 minutes.
Two economists walk down the road.
E1: look, a 100$ bill over there!
E2: if it were one, somebody would have picked it up already!
E1: nods