In 2021, a startup with thin revenue and profits years away could raise tens of millions at a valuation that would have drawn laughter two years earlier. Eighteen months later, the same company couldn’t get its calls returned. The product hadn’t changed. One number had: the Federal Reserve’s interest rate.
That number is the price of money. It decides what a mortgage costs, what a savings account pays, and what a stock or a startup is worth. When you understand how one number sets all three, interest-rate headlines stop being noise.
Annual averages, 2000–2026. Two lines are the same price measured twice: the 30-year mortgage in amber and the federal funds rate in green. The dashed verticals mark the shocks — 9/11, the 2008 crisis, and covid — and policy works with a lag, so this is a rear-view mirror, not a steering wheel. Data: federal funds rate (DFF) and 30-year conventional mortgage (MORTGAGE30US), via the St. Louis Fed (FRED).
What the Fed actually sets
The Fed doesn’t set your mortgage rate. It sets a target for the federal funds rate, the interest banks charge each other for overnight loans. It sounds obscure, and everything else in credit is priced off it.
When the Fed raises the target, borrowing between banks costs more, and banks pass that cost down the line: credit cards, car loans, home equity lines, and mortgages through the bond market. The same move pushes up what savings accounts and money-market funds pay you, because banks have to compete for your deposits.
A cut runs the whole thing in reverse. Borrowing gets cheaper, saving pays less, and money tilts toward spending and risk instead of sitting in cash. The Fed has one lever, and it pulls it to change what the entire country does with money.
Two rules from those paragraphs cover almost every rate headline: up means borrowing costs more and savings pay more; down means the opposite. The rest is detail.
The two ends of the lever
Low rates say borrow, spend, invest. High rates say save and wait. That’s the whole mechanism, and it explains why rate changes move stock prices, house prices, and job postings at the same time.
One part is easy to forget. When rates rise, the pain arrives before the cure. Higher borrowing costs slow hiring and can end jobs before they bring prices down. The Fed’s tool works, and it’s blunt: it hits labor before it hits prices.
What makes a stock “rate-sensitive”
This is the single idea that runs through markets, the economy, and most of what you’ll ever want to know about rates.
A company’s price tag is its future profits, pulled back to today. That discount is set by rates. When a savings account pays 0.25%, a dollar promised a year out loses almost nothing by waiting. When it pays 5%, a dollar promised a decade out is worth far less today, because a saver earns nearly the same with no risk.
Put dollar figures on it and it stops being abstract. A dollar of profit one year out, when rates go from 5% to 6% — about a cent of its present value disappears. A dollar of profit a decade out loses almost a dime. A 30-year promise loses roughly a quarter. Distant money isn’t a little more sensitive, it’s an order of magnitude more sensitive, and the multiplier only grows the farther out you go.
So the farther a company’s profits are in the future, the more its value swings when the Fed moves. An unprofitable growth stock, a startup burning cash, a 30-year bond — all of them are promises of money later. Cheap money makes later money look nearly as good as now. Expensive money makes it look like a bad bet.
Look at what people actually do with that. When the Fed holds rates near zero, a checking account and a money market fund pay next to nothing, so the only way to earn a return is to take on risk — a startup, a growth stock, an illiquid bet. The same saver facing a 5% fed funds rate can get that 5% basically free from a government bond or a savings account, so the risk suddenly doesn’t pay. Yield goes from something you hunt to something you can just sit down and take. The bond that was a poor substitute becomes the whole game.
The mechanism, though, works with a lag, and that’s where the chart is a trap if you steer by it. The Fed raises in March; the lines on the chart keep moving for months after. Policy is aimed at the economy as it will be, but the data it shows you is the economy as it was. Watching this chart is like driving by the rear-view mirror: it tells you the turn you already took was real, not the turn coming up. Distance from profit is sensitivity to the Fed. Everything below is that sentence in motion.
What the 2020s rate cycle showed
In March 2020, the pandemic shut the economy and the Fed cut its rate to 0–0.25%. That was defense, not ambition: cheap money kept credit from seizing while the world waited. Then it stayed near zero through a year of reopenings, vaccines, and stimulus, and the market did exactly what the mechanism predicts.
Future profits looked nearly as good as cash, so anything priced on a distant future inflated. The S&P 500 doubled from its 2020 low to its early-2022 peak. Startups with no profit and no near-term path to one raised money at valuations that assumed success was already earned — some at 40x revenue, some with no revenue at all.
When inflation hit 9% and the Fed hiked fast in 2022, the same math ran in reverse. The doubling became a 19% drop, and startup funding froze almost overnight. The boom and the bust were the same mechanism, running forwards and then backwards. Cheap money didn’t create new businesses. It made distant profit look cheap, and when the Fed raised the price of money, the discount came due.
The cost lands on people
I was at a startup during all of it. Growth was the only question investors asked, and our revenue grew, so we raised at higher valuations and spent as if the future had already arrived. When the Fed hiked, the question flipped to how long the cash would last, the funding round got pulled, and I was laid off with thousands of other startup employees.
Rates don’t lay off a company’s stock. They lay off its people.
Fair to the Fed
The Fed doesn’t deserve a villain’s edit. It deserves a closer look.
Cutting to zero in March 2020 was the right call in a genuine emergency; the alternative was a financial seizure on top of a health crisis. When inflation hit 9.1% by June 2022, the Fed moved from zero to 5.25–5.50% in about a year and a half. That part isn’t hard to defend.
The fair complaint is that it kept the pedal down through 2021, well past the emergency, and the cheap money it printed bulged into every asset it could reach. The Fed can only tune the whole country with one lever. It can’t route cheap money to the productive and away from the frothy, and when it finally pulled the lever, the consequences landed on ordinary jobs — including mine.
Defensive in an emergency, slow off the pedal, blunt by design. Not malicious. Just a lever.
What it means for your money
Rates reach your money at a few specific points, and knowing them is most of the job.
Your mortgage. The rate decides how much house a payment buys. At 3%, a $2,000 monthly payment borrows roughly $475,000; at 7%, about $300,000. Shop the rate as hard as you shop the house, and don’t stretch for a payment you can only afford at today’s rates.
Your savings. High rates finally pay cash, and a high-yield savings account is the right home for an emergency fund. Low rates quietly shrink cash against inflation, which is exactly when the rest of your money still needs to be earning; that’s the point of the invested portion.
Your retirement accounts. They swing either way with the cycle. The people who kept contributing monthly through the 2022 drop were buying in cheap, which is the pattern that compounds.
What not to do. Don’t time the Fed. Rate expectations are priced into stocks before the committee announces them, so reacting to headlines means you’re always late. It’s the same trap as timing the market, better dressed.
Read the dial, don’t bet on the move
Rates are the price of money, and money is the price of everything. That number decides who can afford a house, what a startup is worth, and whether a company keeps payroll for another quarter. You can’t predict its next move, and you don’t need to.
Keep the monthly contribution flowing into a broad, low-cost index fund. Keep an emergency fund sized for a layoff that arrives without warning. Let the Fed pull its lever; your plan shouldn’t move. Cheap money makes headlines. Patient money makes compound interest.
What exactly does the Fed do when it 'raises rates'?
It raises its target for the federal funds rate — the interest banks charge each other for overnight loans — by a quarter- or half-point. Banks pass that cost down the chain, so a small policy move becomes a higher mortgage rate, a higher car payment, and a higher savings yield.
Why did near-zero rates inflate stocks and startups?
Because waiting got nearly free. Low rates make distant profits look almost as valuable as cash today, so companies that expected profits years out were suddenly worth more. Cheap money let startups raise at rising valuations, and the market priced growth as if success were already certain.
Is the Fed to blame for the 2020–22 boom and bust?
Partly, and fairly. Cutting to zero in 2020 was the right defensive call. But rates stayed at zero well after the emergency, and cheap money inflated asset prices. When the Fed hiked in 2022, the same companies deflated — and the jobs they paid for didn't survive the round trip.
Should I change my investing based on interest rates?
No. The market prices rate expectations before they hit headlines, so timing the Fed is timing the market in a better suit. Rates matter most to your direct finances: your mortgage, your credit card, your savings account. Keep automating a monthly contribution to a broad index fund and let the Fed work in the background.
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