As of yesterday, you are temporarily banned from profiting if the stock of Express Scripts (ESRX) goes down, but are free to profit from a decline in the stock price of Medco Health Solutions (MHS).
Confused? Never fear. Here’s a quick primer on what I think is happening.
Yesterday, the SEC asked stock market exchanges to add companies to this initial list (per press release 2008-218), stating: “The Commission expects these lists to cover banks, savings associations, broker-dealers, investment advisers, and insurance companies, whether domestic or foreign, and the owners of any of these entities.”
In response, the New York Stock Exchange (NYSE) and NASDAQ added more than 130 stocks to the temporary ban on short-selling. (See SEC short ban list now covers more than 900 firms.)
Here’s the funky part. Express Scripts (ESRX) is on the expanded list, but Medco Health Solutions (MHS) is not.
As far as I can tell, this happened because the stocks are traded on different exchanges. Express Scripts is traded on the NASDAQ, while Medco trades on the NYSE. According to this MarketWatch story, the NYSE apparently asked its member companies to “self-certify” in order to be added to the list. I’m not sure how NASDAQ generated their list, but they (vaguely) describe their criteria here.
I’ll leave it to the Wall Street boffins to figure out what this asymmetric ban means, but I do note the divergent change in stock prices during yesterday’s down stock market. MHS was down -2.32%, while ESRX was down only -0.23%. Meanwhile, the SEC is already revising the rules, so the situation could change.
P.S. Yesterday’s Wall Street Journal has the contrarian POV that Short Sellers Keep the Market Honest.