Look back to the "too big to fail" banks in '08.

From biggest to smallest, the top three:

AIG controlled $1.05T and market cap crashed from $180B to $3.8B

Wachovia controlled $782B and market cap crashed from $110B to $1.8B

Lehman Brothers controlled $639B and market cap crashed from $60B to $200M.

Massive companies accounting for lots of money in people's retirment accounts. The companies made mistakes leading to what would have resulted or did result in defaulting on their debts. Suddenly billions of dollars vanished from retirement accounts.

We could very easily see a similar cascade of corrections if we get a few more "Alphabet missed earnings" news calls.