S&P 500 Negative Gamma Signals Rising Market Risk

The S&P 500 flipped into negative gamma, signaling rising volatility and a potential trend reversal. Broadcom's (AVGO) $60B debt plans and rising correlations suggest further downside for the index and semiconductor (SMH) sector.

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The S&P 500 fell by nearly 90 bps today and closed below its 10-day exponential moving average for the first time since July 31. That could be important, as that moving average can at times signal a reversal in trend. It is also important that the index has now flipped back into negative gamma, which could mean volatility expands as dealer hedging flows move with the market, based on my math.

Line chart of SPX dealer net gamma exposure over 83 days, fluctuating between about -$70B and +$220B, ending near -$59.5B, indicating dealers currently short gamma

Correlations rose again today, and the semiconductors appeared to see their implied correlations rise a bit faster as well. Basically, we are no longer at a point where the semiconductor ETF’s implied volatility is rising faster than the index’s. That is important in some ways because index volatility had been largely suppressed, and that at least changed today following yesterday’s VIX OpEx.

Something to watch will be whether the VIX continues to rise faster than the VXSMH in percentage terms. If the VIX is rising faster, implied correlations should steadily rise. That would be a sign that the S&P 500 could head lower. When implied correlations fall, the S&P 500 generally rises.

Line chart comparing Implied Correlation Proxy (VIX²/VXSMH², red, 15.13) and Cboe 1-Month Implied Correlation Index (green, 9.46, up 18.99%) from Nov 2025 to Sep 2026, both peaking near 42 in April then declining to lows around 4-6 by July before recent uptick

The 30-year rate rose by 6 bps today, largely reversing yesterday’s decline. More importantly, the Treasury Secretary pretty much confirmed that there has been a lack of liquidity in the 30-year Treasury more recently, and that part of the reason for increased buybacks seemed fairly obvious to me.  However, I’m not sure buybacks will help much, given that the move in rates is not a US problem but a global one.

Well, part of the mystery surrounding why we have been seeing CDS spreads widen across the semiconductor sector may have been solved. Today, it was revealed that Broadcom (AVGO) is looking to raise up to $60 billion in debt to fund its AI buildout. The credit market has been right to worry about increasing debt loads, and it will be interesting to see whether spreads continue to widen now that this news is out. I’m guessing they will widen further, and not just for Broadcom.

Line chart of NVIDIA and Broadcom 5Y CDS mid spreads rising sharply since June 2026, Broadcom to ~118bps, NVIDIA to ~83bps, from ~33bps in Sep 2025

Luckily for Broadcom, $360 has been the put wall helping to support the stock. However, that should be gone tomorrow after the expiration rolls off, and there is a lot of room for the stock to fall on the technical chart if the $360 support breaks.

Daily chart of Broadcom Inc. (NASDAQ) showing price falling from around 300 in January 2026 to peak near 500 in June, then declining to close at 364.03, up 0.43%, with EMA10, SMA50, support/resistance lines near 291-440, and RSI at 36.19 indicating recent downward momentum

To avoid confusion, the delta chart for the SMH has reverted to the standard convention, with calls positive and puts negative, from the version shown on Tuesday, which attempted to display the exposure from a dealer perspective. There is still a large amount of call exposure above the current spot price that is due to decay, and overall net delta exposure remains positive. So there is a chance that if the SMH breaks the put wall at $560, the decay of the calls, combined with the puts becoming energized, could lead to a further drop in the sector.

Chart showing SMH call vs put delta exposure by strike price, with current price at $563. Largest call delta near $550 and $600, largest put delta near $500, $550, and $630, indicating key options positioning levels

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