Swift and bold action has backed up these words.

The Fed slashed its policy rate to zero and, more importantly, committed to buying Treasuries and mortgage-backed securities without limit. It is also putting cash directly into companies' hands.

On March 17 it restarted a financial-crisis program for purchasing commercial paper—debt that companies issue to meet short-term obligations.

And on March 23 it unveiled plans to start buying corporate bonds—for the first time ever.

These moves into corporate lending are significant.

With stay-at-home orders covering 150 million Americans, consumer spending has ground to a halt. This deprives businesses of the cash they need to operate—to pay for supplies, rent, wages and the like. The Fed is therefore helping businesses borrow in order to avoid mass closures and layoffs.