How 'cash' at companies became risky - MarketWatch:
"...as strange as this may sound, Bristol-Myers Squibb was the latest company to do the equivalent of taking a charge against cash when it announced a $275 million impairment of debt investments that held such things as surprise! subprime and home-equity loans.
Companies don't really take charges against cash, of course, but investments that double as cash might as well be cash. Auction-rate securities, as these arcane investments are called, were deemed so safe that they sat on the balance sheet not far from Treasurys in a near-cash category called 'marketable securities.'
Until a few years ago, before a change in accounting rules, Bristol-Myers accounted for auction-rate securities as actual cash. They are so much like cash that they yield just a fraction of a percent above cash and, as Bristol-Myers regulatory filings say, can 'be liquidated for cash at a short notice.'"
Thanks to Mark P for sending this article to me.