The Twitter convention for referencing a stock is to put a dollar sign in front of the ticker symbol. For example, a tweet that contains $MSFT is talking about the stock for Microsoft Corporation. The tweet likely contains a link to an article about the company’s performance, or perhaps somebody’s sentiment about the stock. I got to wondering which stocks get the most tweets.

Twitter has a very easy to use API, and fairly liberal usage restrictions. It was a matter of a few minutes to get a list of the stocks on the S&P 500 and write a simple program that does a Twitter search for each stock and computes a “tweets per hour” figure for each stock. From there, it’s a simple matter of sorting to come up with the most-tweeted stocks.

If you assume that Twitter is a reliable proxy for overall chatter about stocks, then you can say that the stocks below are the 20 most talked about stocks. I don’t know enough about the market to say with any certainty that the assumption holds true, but the list below does include more than just technology companies. So I suspect there is at least some correlation between tweets and overall market sentiment.

I was somewhat surprised to find Walgreen (WAG) in the top 10. PEP, FCX, MHS, and X were a bit surprising, too. The most likely reason for Express Scripts (ESRX) being on the list is that they announced a merger with Medco yesterday. Or was it Wednesday? Either way, Twitter reflects the recent buzz about ESRX.

Note that the list above is just a snapshot. I did a one-time snapshot to get the recent tweets for each stock at one particular time. There are all kinds of things that could skew the data in a single snapshot. You would need several snapshots per day over a few days to get a more reliable list. For my purposes, a single snapshot is just fine.