# Tag Info

Accepted

### Why is NPV a biased measure?

There is no statistical "bias". It is just that NPV and IRR can provide different rankings to projects. For example consider a project with a small initial investment and positive cash flows ...
• 1,222

### Why do we usually model returns and not prices?

Somewhat sloppy, you could say this. Prices are totally unpredictable and follow a brownian motion. Therefore you can not predict prices. However, returns have structure so you can predict returns.
• 245

### Returns of an interest rate swap

I think the best concept of return for the interest rate swap is (2-0)/m, where m is the outlay for initial margin. This is rarely calculated at an institution holding a large portfolio of swaps, ...
• 13.7k
Let us specify the floating-leg rate reset dates to be $T_\alpha, T_{\alpha+1}, \ldots, T_{\beta-1}$, payment dates $T_{\alpha+1}, \ldots, T_{\beta}$. Set the day count fraction to \$\tau_i \equiv T_{i+...