The HY OAS is the extra yield junk-rated corporate bonds pay over comparable Treasuries — real credit-market pricing, not a survey.
ICE BofA's US High Yield Index Option-Adjusted Spread (FRED ticker BAMLH0A0HYM2) strips out embedded call-option value and reports the spread over the Treasury curve in percentage points, published daily. Widening means junk bonds are cheapening relative to Treasuries; narrowing means credit markets are getting more comfortable.
A widening spread is one of the more reliable early-warning signals in market history — credit investors reprice risk before equity markets fully catch up, since a bond default destroys principal directly while a stock decline is "just" a paper loss until sold.
Bond investors are demanding more compensation to hold junk-rated debt — real capital being repriced for more perceived default risk.
It has historically tended to widen before equity drawdowns, but it is a leading context signal, not a guaranteed timing tool.
FRED publishes ICE BofA's series (BAMLH0A0HYM2) daily — Quantustik's market-conditions model consumes the same series.
Browse all S&P 500 tickers to see this metric applied to individual companies.
Educational research only — not investment advice.