This project investigates option pricing and hedging strategies based on WBA stock. It covers key concepts including Put-Call Parity, Implied Volatility, Delta Hedging, and Volatility Spreads.
Put-Call Parity is a fundamental concept in finance that defines the relationship between European call and put options with the same expiration date and strike price. When violated, it provides arbitrage opportunities.
- Equation 1: ( S + P > C + Ke^{-rT} )
Strategy: Buy a call, sell a put, and short the stock or lend money at the risk-free rate. - Equation 2: ( S + P < C + Ke^{-rT} )
Strategy: Buy a put, sell a call, buy the stock, or borrow money at the risk-free rate.
- Risk-Free Rate Assumptions: May not reflect actual rates during the option's lifetime.
- Time to Expiration: Small errors could distort discount factors.
- Transaction Costs: Ignoring commissions, bid-ask spreads, etc., could reduce or eliminate profits.
- Liquidity: Illiquid options might hinder execution.
- Model Limitations: Assumes European-style options in a perfect market.
Implied Volatility (IV) represents the market's expectation of future price volatility. It is forward-looking compared to historical volatility, which is backward-looking.
- Used the Black-Scholes Formula to calculate theoretical option prices.
- Employed the
Goal Seek
function to adjust IV until the theoretical price matched the trading price.
- Volatility Smile:
- For put options, IV is lowest at at-the-money (ATM) strikes and increases for in-the-money (ITM) and out-of-the-money (OTM) options.
- Similar behavior was observed for call options.
- The downward slope for high IV and upward slope for low IV reflects mean reversion.
Factors like put-call parity violations, market performance, and investor sentiment contributed to variations in IV.
Delta Hedging is an options trading strategy to mitigate price change risks in the underlying asset.
- Calculated Delta (( \Delta )) using ( \Delta_{Call} = N(d1) ).
- Adjusted the portfolio daily to remain delta-neutral by buying or selling shares as Delta changed.
- Compared two approaches:
- Using Implied Volatility
- Using Historical Volatility (22-day)
- Cost of Shares: Price paid or received for hedging.
- Cumulative Costs: Includes interest (4.7%) for borrowed shares.
- Daily rebalancing ensured minimal risk.
- The two approaches yielded different profit and loss results, highlighting the impact of volatility estimation.
A volatility trade was constructed by comparing historical volatility (22-day) with option implied volatility.
- Constructed a volatility spread using both calls and puts.
- Plotted the payoff function for the spread.
- Calculated the payoff on the option's expiry.
- Call Spreads and Put Spreads were compared for cost-effectiveness.
This project provided insights into the application of advanced financial concepts for real-world trading scenarios. Key learnings included:
- Identifying arbitrage opportunities through Put-Call Parity.
- Using Implied Volatility to understand market sentiment.
- Implementing dynamic Delta Hedging to minimize risk.
- Constructing effective Volatility Spreads for profitable trades.
By addressing risks and model limitations, the analysis demonstrates the complexity and challenges of financial modeling in live markets.