Not true. If there is a lower circuit right at opening bell, you cant exit anyways. So you have no choice but to hold your stock till the circuit breaks. Maybe days.
I trade small caps/pennycaps also. sometimes, stock will be locked in upper circuit for many days. They go up 30-40%. Right on top, there will be a day when the circuit will break and the stock will end at day's low. This is your first sign to get out. If you miss this exit then stock can turn and go into lower circuit for the next few days again. Ive seen some of my stocks go up like this and turn down to lose 50% of the gains. This is very very common in these kind of stocks.
Edit: If you were talking about intraday, its very different. Even then, should price go against your position very quickly and get locked in a circuit, you will get trapped.