Rearrange put-call-parity and, with rates known, the only unknown left is the dividend the market expects before expiry. Doing this across expirations produces a term structure of expected payouts — a genuine forecast produced by people with money at stake.
It is most informative when it disagrees with consensus. A dividend implied well below the current payout is the options market pricing a cut, often earlier and more decisively than analysts do. It also explains option prices that otherwise look mispriced.
Example: XYZ at $50 pays $0.30 a quarter. Parity on the 90-day chain implies a $0.12 dividend. Either the market expects a cut, or your borrow rate assumption is wrong — and in a hard-to-borrow name the second explanation is usually the right one.
Related: put-call-parity, implied-forward, dividend-risk, early-assignment