By the way if the monthly bonus out early next month, will they use previous statistics or they only calculate statistics based on the last 15 days?
No one knows the actual answer here. We may not receive the same bonus amount even if they consider 30 days gameplay activity for an early monthly bonus. They might calculate the bonus in the new pre or post monthly bonus system. It has small contribution from the house edge.
I quite wonder, how much my monthly next month with just deposit 500$ & waggering under 5,000$ ~XD
Don't expect much if you are in profit with the small wager. You will receive a better amount if you have lost that decent amount. November month hasn't ended yet, and we have already started to discuss about December monthly bonus

. Users will be disappointed if Stake team doesn't send an early monthly bonus like the previous year.