I just started reading Hull's book, and I got stuck in an example where a financial institution has sold for $300,000 a European call option on 100,000 shares of a non-dividend-paying stock.
- Stock price is 49
- Strike price is 50
- $r$ is 0.05,
- vol is 20%,
- $T$ is 0.3846
The example says
Initially, the value of the written option is 240,000. In the situation depicted in Table 18.2, the value of the option can be calculated as 414,500 in Week 9. Thus, the financial institution has lost 174,500 on its short option position. Its cash position, as measured by the cumulative cost, is 1,442,900 worse in Week 9 than in Week 0. The value of the shares held has increased from 2,557,800 to 4,171,100. The net effect of all this is that the value of the financial institution’s position has changed by only 4,100 between Week 0 and Week 9.
My question is: where did the numbers 4,171,100 and 4,100 come from?