The following would be how buyback/refill calculated according to [Passed] Standard and Core Please check.
Circulating NuBits (CN) = 742015.019400 NBT
BTC target (BTCTR) = 15%
reserve target = CN x BTCTR = 111302.25291 NBT
reserve velocity (BTCV) = 5%
The standard (ST) = reserve velocity x (T4BTC - reserve target) = 0.05 x (T4BTC - 0.15 x CN)
= 0.05 x (131.743468 BTC x 456.16 USD/USNBT - 0.15 x 742015.019400 NBT)
= -2560.31
ST < -2500, sell |ST| amount ($2560.31) of NSR
T4 reserve in PPC (T4PPC) = 0
PPC target (PPCTR) = 5%
PPC velocity (PPCV) = 10%
PPC threshold (PPCTH) = $1000
auxiliary reserve flow (F) = (PPCTR / BTCTR) x (PPCV / BTCV) = (5%/15%)x(10%/5%) = 2/3
PPCTH x F = $1000 x (2/3) = $666.67
Since ST(-2560.31) < -(PPCTH x F), sell (F x ST = -1706.83) amount of PPC (oops we don’t have any PPC)
Peercoin standard (PPCST) = PPCV x (T4PPC - PPCTR x CN) = 10% x (0 - 5% x 742015.019400) = -3710.075097
PPCST is not > PPCTH($1000), there is no selling PPCST amount of PPC