I asked the blogger for more details. He said U.S. law requires a minimum of $25,000 in the brokerage account to day trade. If you have more than this minimum, fine: you can day trade on U.S. exchanges in a margin account. If you have less, “they allow 4 day trades before they shut your trading down … only allowing you to exit positions.” Trading can resume after a certain period of time. Documents on the Internet confirm the restrictions.

The changes were passed back in 2001, so maybe some of you out there already knew this. But I did not (or had forgotten it). One thing you may not know, though, is that some brokers apparently enforce the rule rigorously while others do not, according to tipster.ca.

One wonders if the greater presence of smaller day traders has imparted more “noise” to the prices of stocks listed on the TSX as opposed to U.S. exchanges. Could this be a publishable research paper for some academic to write up?

Now, let’s get down to the nitty gritty. The value of its Thomson Corp. shares is a major component of the Thomson family’s net worth. According to the most recent Thomson management information circular, issued on April 4, as of March 20 the Thomson family, through its investment vehicle Woodbridge, owned 450, 611, 770 common Thomson shares. We know from a management information circular issued in late February that Thomson Corp. shareholders would “continue to own their existing common shares,” when the acquisition was completed. As I post this Thomson Reuters Corp. shares are currently trading at just more than $36 on the TSX. That means the value of the Thomson family’s shares is around $16.3 billion, which is down some $3.6 billion from when we calculated the familly’s net worth for the 2007 Rich 100. Back then (Oct. 12, 2007), the stock closed at $44.39, and the shares were worth $19.9 billion. It should also be noted they owned some 2.6 million fewer shares when we made our 2007 calculation.

While the Thomson family is hardly in the poor house, $3.6 billion, even if it’s just a paper loss, is nothing to sneeze at. In light of the current U.S. economic environment Thomson Reuters does face uncertain times, but the company seems confident in its future: it also announced it may repurchase as much as US$500 million of its shares by the end the year. Looking out a bit, May 1 is the date Thomson Reuters will release first quarter results, as well as a 2008 financial outlook. As for the Thomsons, we’ll just have to wait until the 2008 Rich 100 to see how Thomson Reuters’ performance affects their place in the overall ranking. Truth be told, my bet’s on them to hold on to the number one spot, but you never know….