3 ms·> 10x about every 4 years (around 20% APR) 1.2^4 is ~2x. 10x in 4 years is ~80% APR.by mysecretaccount 5y ago> 10x about every 4 years (around 20% APR) 1.2^4 is ~2x. 10x in 4 years is ~80% APR.