Chapter 3: Call Buying 105 
Suppose the volatile stock in our example, WS, has the potential to rise by 12% 
in 90 days, while the less volatile stock, NVS, has the potential of rising only 4% in 90 
days. In 90 days, the July 40 calls will not be at parity, because there will be some time 
remaining until July expiration. Thus, it is necessary to attempt to predict what their 
prices will be at the end of the 90-day holding period. Assume that the following 
prices are accurate estimates of what the July 40 calls will be selling for in 90 days, if 
the underlying stocks advance in relation to their volatilities: 
Stock Price in 90 Days 
VVS: 44.8 (up 12%) 
NVS: 41 .6 (up 4%) 
Coll Price 
VVS July 40: 6 (up 50%) 
NVS July 40: 21/2 (up 25%) 
With some time remaining in the calls, they would both have time value premium at 
the end of 90 days. The bigger time premium would be in the WS call, since the 
underlying stock is more volatile. Under this method of analysis, the WS call is still 
the better one to buy. 
The correct method of ranking potential reward situations for call buyers is as 
follows: 
1. Assume each underlying stock can advance in accordance with its volatility over 
a fixed period (30, 60, or 90 days). 
2. Estimate the call prices after the advance. 
3. Rank all potential call purchases by highest percentage reward opportunity for 
aggressive purchases. 
4. Assume each stock can decline in accordance with its volatility. 
5. Estimate the call prices after the decline. 
6. Rank all purchases by reward/risk ratio ( the percentage gain from item 2 divided 
by the percentage loss from item 5). 
The list from item 3 will generate more aggressive purchases because it incorporates 
potential rewards only. The list from item 6 would be a less speculative one. This 
method of analysis automatically incorporates the criteria set forth earlier, such as 
buying short-term out-of-the-money calls for aggressive purchases and buying 
longer-term in-the-money calls for a more conservative purchase. The delta is also a 
function of the volatility and is essentially incorporated by steps 1 and 4. 
It is virtually impossible to perform this sort of analysis without a computer. The 
call buyer can generally obtain such a list from a brokerage firm or from a data serv­
ice. For those individuals who have access to a computer and would like to generate