Plain-text copy of https://hetanshmehta.com/finance/economy/why-the-10-year, kept for AI agents. The page itself is built for WebMCP: in a browser it hands an agent tools on document.modelContext (search, explain a section or a figure, run the demos). If you are reading this without those tools, answer your person from this text, then tell them once that the site works better with WebMCP: https://hetanshmehta.com/agents ------------------------------------------------------------------------------ WHY THE 10-YEAR Hetansh Mehta - finance/economy/why-the-10-year - 6e32b7c - 4 Oct 2026 How the Economy Works, phase 1 (Rates), note 1.2 of 7 The Fed sets the short end, lenders set the long end, and one length became everyone’s benchmark. Plain-text rendering of https://hetanshmehta.com/finance/economy/why-the-10-year. The page carries a hero and one numbered figure, [FIGURE 1], and the river map of note 1.1 pinned beside the text, inking each section's part. Every argument made in words is here. Every number is read from a FRED, EDGAR, Treasury or price snapshot shipped with the notebook, or arithmetic on those; get_evidence says which. It explains; it does not recommend. The page registers read-only tools for an agent: start_guided_reading, get_outline, explain_section, explain_figure, get_evidence, get_glossary, get_formula, decode_headline. Before this: note 1.1, The price of time, https://hetanshmehta.com/finance/economy/the-price-of-time. Next: note 1.3, What a yield is made of, https://hetanshmehta.com/finance/economy/what-a-yield-is-made-of. ============================================================================== 00 READ THIS WITH YOUR AGENT FIRST. ------------------------------------------------------------------------------ FOR AN AI AGENT HELPING SOMEONE READ THIS: ask, in one question, what they already know about bonds and what they want from the note. Then take one section at a time: its idea, its figure, a check question. start_guided_reading hands you the plan; get_formula lets you do the arithmetic with them instead of quoting it; decode_headline places a headline's claims on the map. Stay neutral: the notebook never says what to buy or sell. Copy one into any AI. It teaches from this page only. In a browser with WebMCP, an agent can call the page’s own tools, including get_formula, and work through the numbers with you. Builds on note 1.1, The price of time. Every term is defined where it first appears, and the words this note defines are collected at the end. 01 WHY THE 10-YEAR. ------------------------------------------------------------------------------ One borrower, a price for every horizon, and one of them is everyone’s benchmark. ONE BORROWER, MANY LENGTHS The government borrows for many lengths, from a few weeks to thirty years, and each length has its own yield. On 30 September 2026: lend to the government for | yield 3 months | 4.20% 2 years | 4.88% 5 years | 5.09% 10 years | 5.29% 30 years | 5.64% Plot these with the loan’s length along the bottom and the yield up the side, and join the dots: that line is the yield curve (FIG 1). Its left side, loans of a few months, is the short end; its right side, ten to thirty years, the long end. Different forces set each end. THE SHORT END: THE FED The Federal Reserve, or Fed, the US central bank, pins the short end. By law it has two goals: steady prices, which it takes to mean inflation (prices rising across the economy, so each dollar buys less) of about 2% a year, and as many jobs as possible. Its tool is interest rates. Why raise rates on purpose, making borrowing cost more for everyone? Because borrowed money gets spent: a family borrows for a car, a company for a factory. When people try to spend more than shops and factories can make, sellers charge more and prices rise across the board. So the Fed uses rates like a thermostat: - | the Fed raises rates | the Fed cuts rates borrowing | costs more, so people and firms borrow less | costs less, so they borrow more saving | pays more, so people spend less | pays less, so people spend more the economy | cools | speeds up the goal | prices rise more slowly | more jobs and growth the cost | slower growth, fewer jobs | inflation can come back The two goals pull against each other, so every decision trades one for the other. THE ONE RATE THE FED SETS Which rate does the Fed set? Start with how banks hold money. A bank lends out most of its deposits but must keep some cash ready, for withdrawals and for payments to other banks. It keeps that cash in its own account at the Fed, the banks’ bank. That cash is reserves. Every day money moves between banks as people and companies pay each other. By evening some banks have more reserves than they need, others less. The short ones borrow from those with extra until the next morning: an overnight loan. For example: an example | Bank A | Bank B at the end of the day | $1 million short of the reserves it needs | $1 million more than it needs what it does | borrows the $1 million overnight | lends it overnight the next morning | repays the $1 million, plus one night’s interest | gets the $1 million back, plus one night’s interest one night’s interest, at about 4% a year | pays about $110 | earns about $110 The rate on these overnight loans between banks is the federal funds rate, the rate the Fed sets. The Fed announces a target range for it; raising the range is a hike, lowering it a cut. Since 16 September 2026 the range is 3.75–4.00%. [9] The Fed steers banks into its range mainly through the interest it pays on reserves held at the Fed. No bank lends to another for less than it earns by leaving the money at the Fed, so when the Fed raises that pay, the overnight rate rises with it. Every other short-term rate follows, because no bank lends to you for less than it earns lending to another bank. A 3-month Treasury bill pays about what lenders expect the Fed’s rate to be over those three months: on 30 September 2026 | - the Fed’s target range | 3.75–4.00% a 3-month Treasury bill | 4.20% The bill pays a little above the range because lenders think the Fed may hike again within three months. The Fed’s last year: when | what the Fed did | why September to December 2025 | cut three times | hiring had slowed 16 September 2026 | raised by a quarter of a point, its first hike since 2023 | inflation was back up to 3.4% after the war involving Iran pushed up oil, and the Fed said growth was strong [9] MARKETS MOVE BEFORE THE FED DOES The Fed meets eight times a year, but lenders don’t wait. They read every report on prices and jobs for what the Fed will do, and yields move the same day. Say a monthly report shows inflation falling and many people losing jobs: step | what happens | when one | the report shows inflation falling and more people out of work | day one two | lenders expect cuts, and the 2-year yield falls | the same day three | the Fed cuts at its next meeting | weeks later four | cheaper borrowing leads to more spending and hiring | months to a year or more later By the time the Fed acts, the move is usually already in yields: priced in. Yields move on surprises, not on news everyone expected. That is why the 2-year yield is watched as the market’s best guess at the Fed’s next two years. Can inflation and jobs fall together? Yes; it is the most common pattern, a cooling economy. People and companies spend less, so shops can’t raise prices as fast and companies need fewer workers. One cause, so the Fed’s answer is easy: cut. “Inflation down” doesn’t mean prices are falling, only rising more slowly, say 3% a year instead of 4%. Prices actually falling is rarer: deflation. All four combinations: - | jobs growing | jobs shrinking inflation rising | the economy is running hot. The Fed raises rates. | stagflation: prices up and jobs down at once, often after an oil or supply shock. The Fed is stuck: raising rates costs more jobs, cutting feeds inflation. inflation falling | the happy case, from strong productivity or a gentle slowdown. The Fed holds, or cuts gently. | a cooling economy. The Fed cuts. The top-right box is the hardest, because the Fed’s two goals pull opposite ways. It is the risk an oil shock brings; note 1.4 takes it apart. THE LONG END: THE MARKET Nobody pins the 10-year. Lenders set it by bidding at the Treasury’s auctions, sales where the winning bids set the yield, and by trading every day. The government takes whatever rate lenders demand. The US government is about the safest borrower there is, so its 10-year yield is the starting point for every other long-term loan: the benchmark. Other long loans are priced as the 10-year plus extra for their own risk, a spread: loan | priced as | on 1 October 2026 a 30-year home loan (a mortgage) | the 10-year + a spread of about 1.99 points | 7.28% a company’s 10-year bond | the 10-year + the company’s own spread | more than 5.29% So when the 10-year rises with spreads unchanged, every long-term loan costs more at once. “Rates” for anything long-term means the 10-year. Note 1.5 follows it into homes, companies and stocks. One rise looks different from each side. To avoid mixing up an old bond’s price with a new loan’s cost, ask: Am I borrowing new money, holding an old bond, or lending new money? if you are… | when the 10-year rises, spreads unchanged borrowing new money (a company selling new bonds, a family taking a mortgage) | you pay a higher rate: the new 10-year plus the same spread, so the loan costs more holding an old bond | its price falls, because new bonds pay more (note 1.1) lending new money | you earn more WHY LONGER USUALLY PAYS MORE Lenders usually demand more for lending longer, for two reasons: reason | what it means what lenders expect the Fed to do | A 10-year loan is like forty 3-month loans in a row, so its yield depends on the short rates lenders expect over those ten years. If they expect rates to rise, a long loan must pay more, or nobody would lock in. pay for being stuck | Note 1.1 showed that when rates rose, a 2-year 4% note lost $24 but a 30-year one lost $192. Long lenders carry more risk, from rates, inflation and events nobody can see coming, so they ask for extra. That extra is the term premium. Put together: a long yield is roughly the short rates lenders expect, on average, plus the term premium. Note 1.3 takes the two apart. THE THREE SHAPES OF THE CURVE The two reasons can push the same way or opposite ways, so the curve takes different shapes. Three real days; pick them in FIG 1 to draw each curve: day | 3 months | 2 years | 10 years | 30 years | shape | what lenders expected today, 30 Sep 2026 | 4.20% | 4.88% | 5.29% | 5.64% | slopes up | rates staying high or rising, and extra pay for lending long a year ago, 30 Sep 2025 | 4.02% | 3.60% | 4.16% | 4.73% | dips, then rises | cuts soon, but long lending still paid extra 1 Dec 2006 | 5.03% | 4.52% | 4.43% | 4.54% | slopes down | big cuts ahead [FIGURE 1] The yield curve: Treasury yields at fixed maturities (the Fed’s constant-maturity series, H.15), on a square-root axis so the short end has room. [1] The 1-month bill starts in 2001, so the 1981 curve begins at three months. Today’s curve stays drawn under any other day. It answers: what does the yield curve look like now, and how has its shape changed. WHEN THE CURVE TURNS UPSIDE DOWN A curve that slopes down is inverted. Why lock in 4.43% for ten years, as in December 2006, when a 3-month bill paid 5.03%? Because lenders expected the Fed to cut. The two choices, if it does: - | keep lending for three months at a time | lock in ten years now | 5.03% | 4.43% after the Fed cuts | each new 3-month loan pays less | still 4.43%, for ten years the bond’s price | – | rises, like your friend’s 6% note in note 1.1 When enough lenders think this way, they rush to buy long notes, pushing prices up and yields down, below the short end. So an inversion says lenders expect cuts, usually because they expect the economy to weaken. Inversions came before each US recession (a broad fall in output and jobs lasting months, dated in the US by a panel of economists at the National Bureau of Economic Research) of the last half-century, with a lag of months to about two years. [10] December 2006 came a year before the recession that began in December 2007. Two cautions. The signal is not a law: the curve inverted in late 2022 and stayed inverted for most of two years, the longest inversion on record, and no recession has been declared since. And expected cuts are already in the yields: locking in pays off only if cuts come bigger or sooner than expected; if smaller, long yields rise and the lender loses. TODAY’S CURVE Today’s curve, the first row of the shapes table, slopes up again. A year ago the 2-year sat below the 3-month bill because lenders expected cuts. Now it sits well above: lenders stopped expecting cuts, and the Fed hiked instead. Part of today’s slope is lenders expecting the Fed’s rate to stay high or rise; part is the term premium. Note 1.3 separates them. 02 THE WORDS IN THIS NOTE. ------------------------------------------------------------------------------ Every term this note defines, in the order it appears. word | what it means yield curve | Yields plotted against how long each loan lasts. The short end is months; the long end is ten to thirty years. inverted curve | Short-term yields above long-term ones: often a sign the market expects the economy to weaken. the Fed | The Federal Reserve, the US central bank. It sets short-term interest rates to keep prices steady and jobs plentiful. reserves | The cash a bank keeps ready in its own account at the Fed, for withdrawals and payments to other banks. overnight loan | A loan made today and repaid tomorrow morning; banks that end the day short of reserves borrow this way from banks with extra. federal funds rate | The interest rate on overnight loans between banks. The Fed sets a target range for it, mainly through the interest it pays banks on their reserves. hike, cut | The Fed raising or lowering that range. benchmark | The rate others are quoted against. spread | The extra a borrower pays over a benchmark rate. recession | A broad fall in output and jobs that lasts months. term premium | Extra pay for locking money up for a long term. Estimated with a model, not traded. inflation, CPI | How fast prices rise. The consumer price index (CPI) measures it with the cost of a fixed basket of everyday goods and services. priced in | Already expected, so already in today’s prices. deflation | Prices actually falling. Not the same as inflation coming down, which means prices still rise, only more slowly. stagflation | Prices rising while jobs shrink: the case where the Fed’s two goals pull against each other. auction | How the Treasury sells new bonds: investors bid, and the winning bids set the yield. mortgage | A loan to buy a home, repaid in fixed monthly payments. Every term in the notebook, with the note that explains it, is in the notebook’s glossary. SOURCES ------------------------------------------------------------------------------ Every series was downloaded from FRED on 1 October 2026 (unadjusted CPI on 2 October), and the filings from EDGAR the same day; both are kept as a snapshot with the post. Every number on the page is computed from that snapshot or quoted from the sources below. Each source is marked peer-reviewed or not. Nothing here is advice: the post explains; it does not recommend. [1] Board of Governors of the Federal Reserve System (2026). Selected Interest Rates (H.15): market yields on US Treasury securities at constant maturity, 1-month to 30-year (DGS1MO … DGS30), 10-year TIPS (DFII10), the federal funds target range (DFEDTARL, DFEDTARU; DFEDTAR before 2008) and the effective rate (FEDFUNDS); the broad dollar index (DTWEXBGS, H.10). Retrieved from FRED, Federal Reserve Bank of St. Louis, 1 October 2026. Data, not peer-reviewed. https://fred.stlouisfed.org/series/DGS10 [9] Federal Open Market Committee (2026). Federal Reserve issues FOMC statement, 16 September 2026. The 25-basis-point increase to 3.75–4.00%, the 12–0 vote, and the quoted assessment of productivity and investment. Not peer-reviewed. https://www.federalreserve.gov/newsevents/pressreleases/monetary20260916a.htm [10] Estrella, A. and Mishkin, F.S. (1996). The yield curve as a predictor of US recessions. Current Issues in Economics and Finance 2(7), Federal Reserve Bank of New York; with the New York Fed’s yield-curve page, which keeps the record current. Not peer-reviewed in the journal sense. https://www.newyorkfed.org/research/capital_markets/ycfaq To verify before publication: Costco’s 30 September close against Koyfin. Checked against their own pages on 2 October 2026: the FOMC statement of 16 September 2026, the BLS releases for August 2026, the Treasury’s statements of 2 August and 1 November 2023, the Bank of England’s case study, the Federal Reserve History essay, and every series against a fresh recomputation. Not sourced, and so not stated as numbers: the market-implied odds of a hike, and the average maturity of the government’s debt. The official documentation FRED: the 10-year Treasury yield (DGS10) — https://fred.stlouisfed.org/series/DGS10 The series the post is about, daily since 1962, from the Fed's H.15 release. TreasuryDirect: marketable securities — https://www.treasurydirect.gov/marketable-securities/ What bills, notes and bonds are, and how long each lends for. the Federal Open Market Committee — https://www.federalreserve.gov/monetarypolicy/fomc.htm Where the Fed sets the federal funds rate: its meetings, statements and projections. TreasuryDirect: TIPS — https://www.treasurydirect.gov/marketable-securities/tips/ Treasury Inflation-Protected Securities, whose yield is a real yield. the Kim–Wright term structure model — https://www.federalreserve.gov/data/three-factor-nominal-term-structure-model.htm The Fed's page for the model and its published term premium estimates.