So if annually is 4.48% with the FUN holdings does this mean that daily increase interest is 4.48% divided by 365 days that we have in a year?
No. That's a compounded APR.
https://www.investopedia.com/terms/c/compoundinterest.aspBecause interest is paid daily it means the next day's interest is calculated on the new higher amount each day. So with the standard 4.08% APR we pay 0.0109589% per day.
0.0109589 * 365 = 3.9999985
But if you had 1 BTC you don't get 0.00010958 BTC every day. You get 0.00010958 BTC the first day but the second day your balance is now 1.00010958 BTC so you get 0.00010960 BTC and so on for 365 days giving a total interest of 0.04080436 BTC.