Unit 1 · Level 1 · Calls & puts
Puts: the insurance policy
A PUT is the mirror image: the right to SELL at the strike. Own shares at €90 and buy a €90-strike put, and no crash can force you to sell below €90. That's portfolio insurance with a visible price tag. Buy a put without owning shares and it's a defined-risk bet that the price falls.
Free to play. No ads, no token, no account needed to start.
What you get asked
At expiry, a bought put makes a net profit when…
A put gains as the stock falls below the strike, but you only net a profit once the fall also covers the premium. Strike − premium is the put's break-even.
Match each position to what it does for you.
Calls point up, puts point down, but both are bought rights with a known, capped cost.
Buying a put against shares you own works like ___ on your portfolio.
It's called a protective put: you pay a premium, and in exchange a crash can't push your exit price below the strike.
You hold a €90-strike put. The stock closes at €80 at expiry. What is the put worth?
A put's expiry value is max(strike − stock, 0). The right to sell €80 stock at €90 is worth exactly the €10 gap.
You're nervous about a crash but love your shares long-term. Why might buying a put beat selling?
Selling means missing the recovery if you're wrong; a put lets you stay invested with a floor under you. The premium is the price of keeping both doors open. (Tax rules vary by country, but the point here is timing, not tax.) 🐜
The rest of this unit
The right, not the obligation: the contract at the heart of every option.