"TIPS" or "Treasury Inflation Protected Securities" are a special type of Treasury note that offers protection from inflation. Like other Treasury notes, an inflation-indexed security pays interest every six months and pays the principal when the security matures. The difference is that the coupon payments and underlying principal are automatically increased to compensate for inflation as measured by the consumer price index (CPI), published monthly by the Bureau of Labor Statistics. They are considered an especially safe investment because the real rate of return is guaranteed. On the downside, because TIPS are so safe, the rate of return is comparatively low.