Stocks vs bonds — what's the difference?

Markets trade thousands of instruments, but nearly everything descends from two ancient ideas: owning a piece of a business and lending money for interest. Master this fork and the whole zoo becomes navigable.

Two ways to give a company money

Imagine your anchor company needs a billion dollars for a new factory. It has two classic options:

• Sell new shares (equity). Buyers become co-owners. The company never owes them the money back. If profits grow, the owners' slices become more valuable; if the venture fails, their slices shrink — possibly to zero.
• Borrow via bonds (debt). A bond is a tradable IOU: "lend me $1,000 today, I'll pay you interest (the coupon) on schedule and return the $1,000 (the principal) on a fixed date (maturity)." Bondholders own nothing of the company — they own a promise.

Why the risk-and-reward profiles differ

If the company hits hard times, the law lines everyone up: lenders get paid before owners. Bondholders receive their coupons and principal first; shareholders split whatever remains — sometimes nothing. That priority is why, as a general pattern across history:

• bonds → steadier, more predictable, limited upside (the bond itself will never pay more than its coupons + principal — though selling before maturity can return more, or less, than that);
• stocks → bumpier ride, unlimited upside in principle, first in line for pain.

Neither is "better." They're different seats in the same vehicle — and most serious portfolios hold both (the famous "60/40" you'll meet in Portfolio Management is exactly this mix).

Governments do it too

The world's biggest borrower isn't a company — it's governments. US Treasury bonds are the benchmark "safest promise" against which markets measure everything else. When you later hear "yields rose today," it's these government IOUs talking, and the whole market listens. That thread leads into the Macro course ahead.

Try it now

The single most-watched number in world finance, over five years. Read this one carefully — it is a yield, not a price, so a value of 4.674 means 4.674%:

1. Read the current level off the right-hand edge. That is what the world's biggest borrower is paying to borrow for ten years — the "safest promise" everything else is measured against.
2. Now the ownership seat's payout for comparison: Apple's dividend yield, a year of dividends divided by today's share price, below. To use your own company instead, open it in the Terminal and change the symbol there.

Open AAPL.US — dividends in the EODHD Terminal

3. Subtract that yield from the level you read off the chart. The result, in percentage points, is how much more the safe promise pays you today than your company's dividend does. Most large companies leave a gap of several points; if yours comes out negative, you have found a high payer, and the question of why it pays so much is worth more than the number.
4. Question to hold onto: if the safe promise pays what the chart says, how much extra should you demand for the bumpier ownership seat? You have just intuited the risk premium — a concept entire textbooks are built on.