Options & DerivativesCalls, Puts & Financial Weapons
A complete visual guide to financial options — how they work, how their prices respond to strike changes, and whether Warren Buffett was right to call derivatives "financial weapons of mass destruction."
The Basics
What Are Calls and Puts?
A call option gives the buyer the right, but not the obligation, to purchase an asset at a predetermined price (the strike price K) on or before a specified date (the expiry).
When is a call profitable?
A put option gives the buyer the right, but not the obligation, to sell an asset at the strike price K on or before expiry. It is essentially insurance against a price decline.
When is a put profitable?
Call vs Put — Side-by-Side Comparison
| Feature | Call Option | Put Option |
|---|---|---|
| Right to | Buy the asset | Sell the asset |
| Profitable when | Price rises above K + premium | Price falls below K − premium |
| Buyer's view | Bullish (expects price to rise) | Bearish (expects price to fall) |
| Maximum loss | Premium paid | Premium paid |
| Maximum gain | Unlimited (price can rise infinitely) | K − Premium (price can fall to 0) |
| Used for | Speculation on upside, leveraged exposure | Hedging downside, portfolio insurance |
Visual Payoffs
Profit & Loss at Expiry
Both charts below use Strike K = $50 and show the option's payoff (gross) and P&L (net of premium) at expiry as the underlying stock price varies.
Call Option — Payoff & P&L (K = $50, Premium = $5)
Breakeven at $55. Below $50 the option expires worthless; above $55 every $1 rise = $1 profit.
- Call Payoff
Strike Price Sensitivity
How Does the Strike Price Affect Option Prices?
As the strike price increases, a call option becomes less valuable. A higher strike means you need the stock to rise even further before the option pays off — making it less likely to be profitable. The option is further "out of the money."
As the strike price increases, a put option becomes more valuable. A higher strike means you can sell at a higher guaranteed price — the put provides more protection, so buyers are willing to pay more for it.
Option Price vs Strike Price
Current stock price = $50. As strike rises, call price falls and put price rises.
- Call Price
- Put Price
The Buffett Debate
Are Derivatives "Weapons of Mass Destruction"?
Positive Roles of Derivatives
Airlines use fuel futures to lock in costs. Exporters use currency forwards to protect revenues. Farmers use crop options to guarantee minimum prices. Derivatives allow risks to be transferred to those best able to bear them.
Options markets aggregate information about expected future prices and volatility. The implied volatility from options prices (the VIX index) is widely used as a real-time 'fear gauge' for financial markets.
Derivatives allow investors to take positions that would otherwise be impossible — for example, betting on volatility itself, or gaining exposure to an asset class without owning the underlying.
Derivatives increase market liquidity by allowing market makers to hedge their positions, which in turn tightens bid-ask spreads and improves price efficiency for all investors.
Negative Roles & Systemic Risks
Derivatives allow investors to take on far more risk than their capital would normally permit. LTCM's collapse, the 2008 financial crisis (CDOs, CDS), and the 2021 Archegos blow-up all involved derivatives amplifying losses beyond what was anticipated.
Over-the-counter (OTC) derivatives are bilateral contracts with no central clearing. If one party defaults, the other may face catastrophic losses — as seen with Lehman Brothers in 2008, which had hundreds of billions in OTC derivative exposures.
Derivatives enable pure speculation disconnected from the underlying economy. The notional value of global derivatives markets exceeds $600 trillion — many multiples of global GDP — raising questions about systemic fragility.
Complex structured products (CDOs-squared, synthetic CDOs) were so difficult to value that even their creators did not fully understand their risk. This opacity contributed directly to the 2008 financial crisis.
"Derivatives are financial weapons of mass destruction, carrying dangers that, while now latent, are potentially lethal."
— Warren Buffett, Berkshire Hathaway Annual Letter, 2002
Buffett's warning proved prescient: six years after writing this, the 2008 financial crisis — triggered in large part by mortgage-backed securities and credit default swaps — caused the worst global recession since the Great Depression. However, Buffett's own Berkshire Hathaway has also used derivatives extensively, suggesting the issue is not derivatives per se, but their misuse, opacity, and the incentive structures surrounding them.
Pre-Class Assignment — Problem 1
Draft Answers — Click to Expand
These are draft answers for the optional Problem 1 questions. Question (c) requires your personal opinion — please revise before submitting.