Here's my advice. Take the money you were thinking of investing here. Put 1/2 in now. Keep the rest in cash.
This strategy reduces your risk exactly in half!
You seem to be very new to investing. You might not get as big an upside from this strategy, but you seem to be worried about risk and asking about guarrantees and worse-cast scenarios. There are NO guarrantees in pennies -- except that the strategy I outline is guarranteed to cut risk in half.