why is it a bad idea to take -10000 bets all the time?

[pico]

insurance companies do it for a living. your pay premium to place a bet at +10000 that you'll get into an freak accident.

[HedgeHog]

Insurance companies know the true odds and set the premiums accordingly for a +Ev situation for them. That said, what makes you think all 100-1 favs are +EV.

And don't forget the insurance companies also invest that money as well. I just sure hope it isn't in bad paper or stocks right now as you'll never get paid.

[LT Profits]

Because the -10000 in sports has a vig built in, meaning you would win less than the 100 out of 101 times required to break even at no-vig odds of -10000.