I wonder who decided the 15% in the past, 15%… In 1971 US gold reserve was 15% compared with its debts, and that was a turning point when US failed to manage USD pegged to gold.
What a black humor! Nu shareholders were astonishing amateurish in economics.
If you have profit, the reserve ratio dosen’t have to be 100%, maybe 70% is enough according to your revenue level.
But if you have little profit, 100% is impossible even you try to achieve, BTW, if the reserve is partially BTC, you cannot control the reserve ratio on you own because of BTC price volatility. You may get 120% reserve if lucky enough, or vice versa.