no idea but i dont think there are negative numbers :]
Rating limt?

When I look at some members' profiles, their bullet rating is below 100 but never 0. But theoretically 0 should be the bottom line.

Try it yourself!
That's funny. I won't have to try it, it may just happen naturally!

I'd say if you understand how the horsey and pointy guy move then you've at least earned that 100 rating.

USCF floor is 100. Mathematically you could go below zero I think. It only cares about the difference, so there's no dividing by zero or anything.
Chess.com probably has an artificial floor too. Which makes sense, as Darth_Algar points out it's unreasonable to have such a low rating.

Found this link in forums courtesy of JMB2010. A 0 rating.
http://www.chess.com/members/view/timmaylivinalie#games

Found this link in forums courtesy of JMB2010. A 0 rating.
Wow! I guess if one loses enough, they really CAN achieve a
"0" rating! Amazing. That's the first person I've ever seen with one. Thanks MrKornKid.

I...see...it...but I still don't...believe...it...
I'm with you Darth, hard to believe ANYONE could lose every single game! Unless, they really DID do it on purpose!

I...see...it...but I still don't...believe...it...
I'm with you Darth, hard to believe ANYONE could lose every single game! Unless, they really DID do it on purpose!
Well yeah, looking at his game history there's a lot of idiotic crap like this - http://www.chess.com/echess/game?id=6864058. And a lot of games against that same user (now a closed account) all ending in the exact same position with white always resigning after the exact same move. So yeah, obviously purposful, and with an alt account I'd guess.
I'm not sure if I admire the consistancy, or if I feel sorry for the person who has that little to pass their time with.
I was asked by a new member what is the lowest a person's rating can drop to if they continually lose. I didn't know the answer. Does anyone know? Is there a bottom rating?