We laughed when we saw the headline below linked on the popular Drudge Report website this morning.“Apple becomes most shorted company ahead of iPhone launch…”  Here’s a link to the story posted on Telegraph.co.uk.

For those reading this headline that aren’t familiar with the inner-workings of short selling, the assumption might be that investors are turning extremely negative on Apple (AAPL). This assumption would be completely wrong, however.

Yes, when it comes to the $ amount of Apple (AAPL) shares that are sold short, the stock is right at the top of the list at $9.2 billion. (Note that as of the close yesterday, Amazon.com (AMZN) actually had Apple beat in this regards.) But measuring short interest by $ amount is nonsensical because it doesn’t take a company’s overall market cap into account.

Below is a list of the 30 S&P 500 stocks with the highest dollar amount of shares sold short. For each stock, we also include its market cap, its YTD % change, its short interest ratio, and its short interest as a percentage of float.

Short interest ratios and short interest as a percentage of float are the indicators that investors use to measure how true short interest levels. The short interest ratio is the number of shares sold short divided by the stock’s average daily volume.It’s also known as “days to cover” because the number tells you how many trading days it would take for short-sellers to cover all of their shares (based on the stock’s average daily volume).

Short interest as a percentage of float tells you the percentage of a stock’s tradeable share count that are sold short, and this is the reading we use most often when measuring how bearish investors are on a name.

As you’ll see below, most of the names on the list are only there because of their massive market caps. Stocks like Apple and Amazon indeed have a high dollar amount of shares sold short, but their short interest ratios and short interest as a percentage of float are right around 1. That’s actually an extremely low number for these two measures.