[math-fun] Negative yield?

Apparently some treasury bonds have just sold, at government auction, with negative yields: "Inflation Bonds Are Sold With Negative Yield for First Time" at < http://www.nytimes.com/2010/10/26/business/26markets.html >. But what does "negative yield" mean? I feel confident that it does *not* mean that the purchaser of the bond must make periodic coupon payments to the seller. But perhaps it means that the redemption value of the bond at maturation is *less* than the price it is purchased for? (If so, it's hard for me to imagine why it's not better to just keep that money in a safe all those years. Maybe a good safe is too expensive?) --Dan Those who sleep faster are sooner rested.