Given the opportunity though, it still seems like a risk well worth it.
Businesses rarely (if ever) fail because of an acquisition gone wrong. But a acquisition gone right can have great returns.
If Instagram flopped when Facebook bought it, Facebook would still be doing just fine. But since it did go well.. yeah.
So I believe that it's still probably in the investor's best interest if MS does the deal even if it's only like a 35% chance that it isn't a complete failure.