Jim Cramer calls for 'buy and homework' over 'buy and hold': What does he mean?

Investing in individual stocks requires more than just passively owning them.

Jim Cramer calls for 'buy and homework' over 'buy and hold': What does he mean?

Here's our Mailbag email: investingclubmailbag@cnbc.com. Send your questions directly to Jim Cramer and his team of analysts. Make sure to read our weekly Mailbag dispatch to see if your question is one of the ones we pick to answer. Reminder, we can't offer personal investing advice. We will only consider more general questions about the investment process or stocks in the portfolio or related industries.

This week's question: You say "buy and homework" and that an at-home investor should have no more than 10-15 stocks due to it being difficult to keep up with the homework if limited on time. What exactly do you mean by homework? Thank you for all you both do! — Mandy M.