For a long time, money market (MM) yields were so small that it didn't make sense to monitor them. This is not the case in the last few months.
MM's are usually slow to raise their yields when interest rates rise. They are getting higher yields from their commercial paper, repos and other short-term instruments, but they don't immediately pass on the higher rates to their investors. That results in more money in THEIR pockets.
So watch your money market yields and move those funds to where you get the best rates. I moved cash I have to Vanguard from Fidelity and I'm getting a 35 basis points (a basis point equals 1/100 of a percent) increased yield. I've tracked this differential for several months now and it's consistent.
Making money in the market is often done by working the “edges”.
Be smart, be well-read, be aware and be successful.
"I don't look to jump over seven-foot bars; I look around for one-foot bars that I can step over." — Warren Buffett