Commentary  Many investors are noticing that technology stocks are going down much more than the general market recently, and we’ve been getting a number of questions regarding the reason.  This has to do with the expected increase in interest rates, which has been a frequent topic of this column.  This phenomenon is well-known to market professionals and is the result of something called duration. Duration is simply a fancy word for how long it takes to get paid on an investment. Let’s take a simple debt as an example. If a friend owes you $1,000 and promises to pay you back tomorrow, you don’t have to spend a lot of time worrying about interest rates. Now, let’s say you’ll be paid back in a year. That increases the duration (or length of time) involved and depending on the interest rate, you might care a bit more about the value of …