Would I lose value converting to BTC?

[worldtraveller321]

Ok question i have. i have investing in many Alt and Privacy coins etc.
i know later one in order to sell/cash out. i have to put all into BTC, Eth or LTC etc? and sell off.

If my privacy coins at time have good value and markets are going up. lets say i have earned $50 usd with NEM. when i transfer those coins to lets say BTC? would value drop?

as i know i have to do that eventually if i want to cash everything out? thanks