8. Explain the meaning of mean reversion? 9. Explain Girsanov's theorem? 10. The gamma of a delta-neutral portfolio is 30 (per S per S) Estimate what happens to the value of the portfolio when the price of the underlying assets (a) suddenly increase by S2 and (b) suddenly decrease by S2? 11. Why is an Asian option easier to hedge than a regular option? 12. Explain why there are economics of scale in hedging options