Hi karthikeqd,You should always use the same seed. Even better, you should use the same seed for all derivatives that you price. As an anecdote, at some point during the credit crunch, a friend of mine, working for a BB bank that will remain unnamed, was asked to run through a large number of seeds, until he could find a "magic" seed, that would show the smallest loss. Using a single seed eliminates this type of games. But that's the least of the reasons why you should use a single seed. The main one is that you don't want to see daily P&L swings due to non-economic factors. Even more important is that with different seeds you'll see huge swings in your hedges, and this will eat you alive in transaction costs. Also, look into moment matching, i.e. multiply all spot values with a constant so that the forward price is correct. This will reduce your variance quite a bit. Best of luck.