help with this formula

[bigeasy]

can someone show me how to solve this.
Bankroll = [-sigma^2/(2*EV)]*
my sigma is 12
my ev is 1
this is from brucez and i seem to get a negative number.
thanks b

[BruceZ]

can someone show me how to solve this.
Bankroll = [-sigma^2/(2*EV)]*
my sigma is 12
my ev is 1

It's bankroll = [ -sigma^2/(2*EV) ]*ln(r)

It looks like you left out ln(r)? r the risk of going broke that you want. ln(r) is the natural logarithm from your calculator or Excel. If you don't have ln but you have log base 10, you can do log(r)/log(2.718) instead. So if you want a 1% risk of ruin, then

bankroll = [ -12^2/(2*1) ]*ln(.01) = (-144/2)*ln(.01) = -72*(-4.605) = 332 units.

Maybe you squared -12 instead of taking -(12^2)?

[bigeasy]

ty

[thylacine]

ln(r)<0 when r<1