Emergency fund
Cash set aside before you start investing.
An emergency fund is cash kept for surprises, such as a job loss, a car repair or a medical bill, so you never have to sell investments at a bad time.
How much
A common guideline is three to six months of essential expenses, more if your income is irregular. Keep it somewhere safe and easy to reach, such as a high-yield savings account.
With the cushion in place, your monthly investing can keep running through rough patches, which is exactly when it matters most.