[hrmm1231321]

Not entirely true. If you wait for the arbitrage opportunity to occur in the reverse direction, you can rebalance. But you take the risk of waiting days/weeks for a reverse dip opportunity.

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 :)

[chatmasta]

I would expect that the same exchanges tend to be on the same side of arbitrage spreads, for various reasons that could include lack of liquidity.

[hrmm1231321]

If you plot them, you will see the spreads intersect now and then.

However, all the same risks apply e.g. with orders not being processed enough.