Post-Fed World: Headless Chickens Meet OPEX Triple Witching | SPX Market Briefing | 18 Sep 2025

The thing we’ve been waiting for all week has finally arrived – we’re in a post-Fed world, and what a bloody circus it was.

Fed delivered the expected 25 basis point cut (first of the year) with another 50 basis points expected before year end. Then came the press conference nonsense that was spewed in typical central bank fashion.

The markets responded exactly as you’d expect: running around in circles like headless chickens before eventually settling down like nothing had happened.

For my systematic purposes, SPX yoyo’ed wildly up and down, then settled relatively unchanged. But ES futures overnight were pumping higher by 60 or so points as I type.

SPX Market Briefing:

Yesterday’s Fed circus is behind us, but Friday’s OPEX triple witching could make yesterday’s volatility look like a gentle breeze.

Current Systematic Status:

• Fed Decision: 25bp cut delivered, 50bp more expected by year end

• SPX: Bull swing still active, profit exit potentially imminent

• ES Futures: Pumping 60+ points overnight, confirming bullish continuation

• Range Status: Potential break higher could create fresh entry opportunities

The Post-Fed Reality:

The systematic approach handled Fed day exactly as designed. While discretionary traders got whipsawed by the yoyo action, mechanical positioning stayed consistent. The bull swing that was established weeks ago continues working beautifully.

ES futures pumping overnight suggests the initial Fed reaction settled into bullish continuation rather than uncertainty. This should take us out of the newly created range and offer up fresh systematic opportunities.

Friday OPEX Triple Witching Tsunami:

Here’s what should have everyone’s attention: Friday is set to be one of the largest OPEX events on record, with over $1.1 trillion in delta notional expiring for the S&P 500. Nearly 90% of those positions are call options.

As these call-heavy positions expire, dealers will need to unwind their hedges. This process could remove the support that’s been stabilizing the market throughout this grinding higher phase. For systematic traders, that shift opens the door to sharper swings and directional moves as fresh positioning takes hold.

Crash Season Reality Check:

We’re in crash season – have I mentioned that? I’ll be banging that drum until we either pop ‘n drop or exit gracefully stage left through the October stage door.

The combination of massive option expiry, dealer hedge unwinding, and seasonal weakness creates a perfect storm for increased volatility. Systematic approaches thrive in these environments because they’re built for uncertainty rather than grinding predictability.

Today’s Systematic Plan:

• Bull Swing: Monitoring for profit exit signals as overnight strength continues

• Range Break: Watching for fresh entry opportunities post-Fed positioning

• OPEX Preparation: Ready for increased volatility and directional clarity

• Premium/Lazy Poppers: Standing by for deployment as market motion resumes

Other than that, we’re back in motion looking for entries and setups. The post-Fed world brings fresh opportunities for those patient enough to wait for proper signals.

Fun Fact:

It is the first time since 2024 that the Fed cut interest rates while BTC price was above $115,000 and equities were near record highs.

Trade well,
T2 Markets

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