LiveCode Forums.

Is there a limit on how big a stack be memory wise

Memory-wise is the only practical limit; the logical limit in the current version is 4GB. That said, the number of cards can become cumbersome for the engine to handle after about 5,000 or so. But if you have fewer cards and are loading them up with tons of graphics and scripts, your limit will be the amount of available RAM up to 4GB.