Mark-to-market

I’ve been hearing ‘mark-to-market’ alot over the last two or three weeks, but just finally checked it out on Wikipedia. The initial description is a tad fuzzy, so here’s the simple example mercifully provided…

Example: If an investor owns 100 shares of a stock purchased for $40 per share, and that stock now trades at $60, the “mark-to-market” value of the shares is equal to (100 shares × $60), or $6,000, whereas the book value might (depending on the accounting principles used) only equal $4,000.

Similarly, if the stock falls to $30, the mark-to-market value is $3,000 and the investor has lost $1,000 of the original investment. If the stock was purchased on margin, this might trigger a margin call and the investor would have to come up with an amount sufficient to meet the margin requirements for his account.