[randomfool]

If I invest right now, what are the chances that this round strikes it rich? The problem is that if a breakthrough is not achieved in this particular round then the company essentially goes bankrupt and my investment is worth zero.

Quantum is far enough away that unless you have deep pockets it's a donation to a charitable cause. The capital requirements are large enough that profits will be sucked up by later investors who would sooner let the company go bankrupt than let you get a decent return on your money.