Tips sold with negative yield

For the first time ever, inflation-protected Treasury bonds sold with a negative yield. Investors bought $10B of five-year TIPS yesterday with a yield of negative 0.55%, in a bet that the Fed will be successful in stimulating the economy, boosting inflation and making the TIPS more valuable. If the investors turn out to be wrong and inflation doesn't appear as they expect, they could end up paying to lend money to the government.

See WSJ article.