Op I advice make u too keep eyes down as others dey drop their opinions for here and believe e go also help u because of u really know the risks behind keeping it funds for exchange u for don let ur friend know am or u for no even bring am up here.
So the Koko be say exchange no good to store values for too long because the security network dey very poor to withstand some kind serious internet attacks and the custodian risk be say u as individual no dey completely full control of your private keys but the operative authorities.
So tell ur frnd to transfer em funds to the custodian wallet network where em funds go dey well safer for am cus there na only em go dey control the funds with full time of private and security keys.