Where do bonds come from, and where do they actually trade?

Stocks are born once in an IPO and then trade on an exchange with a visible order book. Bonds work differently at both ends — and the differences explain almost everything about why this market feels invisible.

The primary market: where bonds are created

The primary market is issuance. Money flows from investors to the borrower, and a new security comes into existence. Two very different mechanisms dominate.

Government auctions

Large sovereigns sell debt by auction, on a published calendar, in standardised sizes. Bidders submit:

• Competitive bids — "I'll take $50 million at a yield of 4.25% or better."
• Non-competitive bids — "I'll take $10 million at whatever the auction clears at." (This is the route small investors use where retail access exists.)

The treasury fills bids from the most attractive yield upward until the offering is sold. The US Treasury has used a single-price (uniform) auction for all marketable securities since 1998: every winner pays the same stop-out price — the yield of the last bid needed to complete the sale. Many other sovereigns, including the UK for conventional gilts, along with Germany, France, Japan and Canada, instead run multiple-price auctions, where each winner pays what it actually bid. The convention is a property of the issuer, not a universal rule.

Auction results are published and closely watched. The bid-to-cover ratio — total bids divided by the amount offered — is a widely cited gauge of demand: a $50 billion auction receiving $125 billion of bids has a bid-to-cover of 2.5. Practitioners read these numbers as a snapshot of appetite on the day, not as a signal about the future.

Corporate syndication

Companies do not auction. They hire investment banks (the syndicate) to run a book-building process:

1. The company announces an intended issue — size, maturity, purpose.
2. Banks market it to institutional investors and collect indications of interest at various yields.
3. Initial price talk gets tightened or widened as the order book fills.
4. The deal is priced, allocated among investors, and settles days later.

A worked example. Northwind Industries issues $500 million of 10-year bonds. Initial price talk: government yield +175 basis points. Orders arrive totalling $1.8 billion — 3.6× oversubscribed — so the syndicate tightens the spread to +150 basis points, meaning a lower yield and a lower borrowing cost for the company. Final terms: 5.0% coupon, priced at 99.50.

At 99.50 the company receives $497.5 million per $500 million of face value, and repays $500 million at maturity. That small discount is standard practice — it nudges the effective yield fractionally above the coupon and helps the deal trade well on its first day.

The secondary market: where bonds change hands

Once issued, bonds trade over the counter (OTC) — dealer to dealer, dealer to client — not on a central exchange. This one structural fact drives everything retail investors find strange about bonds.

• No single price screen. There is no consolidated tape like a stock exchange has. Prices come from dealers, and different dealers can quote the same bond differently at the same moment.
• Dealers hold inventory. A bond dealer buys bonds onto its own balance sheet and sells them out again, earning the bid-ask spread. It is a principal, not a matchmaker.
• Enormous fragmentation. One company might have a single class of common stock and twenty different bonds outstanding — different maturities, coupons, seniorities, currencies. Each is a separate instrument with its own price and its own liquidity.
• Most bonds barely trade. Newly issued and government bonds trade constantly. A ten-year-old corporate bond may not trade for weeks — because the pension fund that bought it intends to hold it until it matures.

Some transparency has arrived. In the US, TRACE requires post-trade reporting of corporate bond transactions, so executed prices become public shortly after the fact. Electronic platforms now handle a meaningful share of volume. But the market's centre of gravity is still relationship-based and dealer-intermediated, and there is no realistic prospect of it looking like an equity exchange.

Why this matters to a reader of prices

When you see a bond "price," ask what it is. A dealer quote? A recent executed trade? A model-derived evaluated price from a pricing service, estimated from similar bonds because this one hasn't traded? All three appear on screens. For a thinly traded bond, the third is common — the price is an informed estimate, not a transaction. Knowing which you are looking at is basic bond literacy.

In the data

Every Treasury bill carries a security number, its CUSIP, and that is where the two markets separate. "Four weeks" is a permanent label, but the bill behind it changes each time the primary market auctions a new one. The table shows the handover on two consecutive days.

Follow the label and you are watching a market: the daily secondary-market quote on whichever four-week bill was auctioned most recently. Follow the security number and you are watching one bill's short life, from auction to repayment. A long history of "the four-week yield" is dozens of different bills spliced together.

Try it now

1. Explain the difference between a competitive and non-competitive auction bid in one sentence each.
2. In the Northwind example, compute the cash raised at a price of 99.50 on $500 million face. ($497.5 million.) Then say who bears the $2.5 million difference and when.
3. Below is a year of daily turnover in one listed share. Every bar is a count somebody kept, because every trade crossed one exchange. Now try to imagine the same chart for a government bond: the yield series this course uses carries a volume of zero on every single row — not missing data, but the absence of any consolidated tape to count. That asymmetry, not size, is the reason the next unit exists.