Triple-C Bond Yield Gap Exceeds 9% After Five Prior S&P 500 Signals

By Olivia Hart

The triple-C versus single-A corporate bond yield gap has exceeded 9%, above the 8% level that preceded at least five S&P 500 drawdowns since 1999, according to MarketWatch’s review of FactSet data. The gap first reached 8% on Sept. 24 and now stands above 9%, while the S&P 500 sits about 3.5% from its highs, according to the report.

Goldman Sachs’s Bobby Molavi, head of European execution services, flagged in a note to clients “the disappointing stock-market results that have ensued when the yield difference between the two classes of corporate debt reaches 8%.” MarketWatch, using FactSet data, found at least five previous instances at that level: 1999, 2000, 2008, 2015 and 2020.

What is the signal measuring?

MarketWatch identifies the signal as the yield gap between debt rated triple-C and single-A. Its wording, however, is not internally consistent.

The report calls both grades junk bonds, then shifts to single-B, describing that category as vulnerable and triple-C as carrying a “substantial risk of default.” It offers no reconciliation between single-A and single-B. That leaves the ratings explanation less precise than the numerical signal.

The inconsistency does not change the reported 8% threshold. The takeaway is simple: the numerical signal is clear, but the ratings explanation is not.

What happened after earlier 8% signals?

MarketWatch’s history provides three examples beyond the two crisis periods. It described the 1999 episode as hitting with a lag, while calling the 2000 and 2015 cases potentially more illustrative.

• 1999: On March 31, the S&P 500 stood 2% below its peak. It climbed for three months before falling 12% by mid-October.
• 2000: On Jan. 3, the index was just 1% below its highs. It ultimately slid 17%.
• 2015: On Nov. 30, the index sat a little over 2% below its high. It then fell as much as 14%.

In every one of those three cases, the index had already left its peak when the threshold registered. The gap therefore marked an existing equity slowdown rather than a reliable countdown to the next leg. The takeaway: each prior warning arrived after equities had already retreated from their highs.

What did the 2008 and 2020 episodes show?

In 2008, the S&P 500 had already tumbled 43% during the global financial crisis when the 8% gap appeared. It ended with a 53% drawdown, and MarketWatch said the subsequent declines were not much worse than the losses already recorded.

The 2020 episode also followed a fast initial shock. A few weeks after COVID-19 was discovered in the West, the index had already fallen 24%; its worst drawdown reached 27%. In both cases, the bond signal arrived after much of the first move had happened. The takeaway: those two episodes make the threshold look late as well as bearish.

What does the current signal establish?

MarketWatch reported that the present gap had widened by more than one percentage point beyond the watched 8% level. The S&P 500’s 3.5% distance from its high is much smaller than the 43% and 24% losses already recorded in 2008 and 2020, yet slightly larger than the 1% to 2% early gaps in 1999, 2000 and 2015.

That comparison does not establish a target. The 1999 index rose for three months after the first signal, while the other episodes produced declines of different sizes over different periods.

MarketWatch did not forecast an index level, a timing window or a specific drawdown, and it did not supply a model linking the gap to a set percentage loss. Its five cases establish co-movement, not causation.

For investors, the forward signal is narrower than the headline suggests: MarketWatch’s five cited periods show a wider bond gap alongside weaker equity returns. The report supports watching both series together, not treating either as a stand-alone forecast.

The next test is whether the S&P 500 falls farther from its high while the gap remains above 9%, a pattern consistent with prior episodes without proving causation. The bond market has raised a credible warning, but the record supplies risk, not certainty.