Will Alphabet Stock Surge After Oct. 28?

Alphabet (NASDAQ: GOOG)(NASDAQ: GOOGL) reports Q3 2026 earnings after the market closes on Oct. 28. Wall Street analysts have an average revenue estimate of $127.8 billion, which would be a 25% year-over-year increase, and earnings per share (EPS) of $3.

Last quarter, Alphabet easily surpassed revenue expectations -- and its share price still ended up falling 7% the next day. Based on the tech giant's recent track record, investors probably shouldn't feel too confident about which direction Alphabet stock will move immediately post-earnings.

Image source: The Motley Fool.

What history says about Alphabet's post-earnings performance

The way Alphabet stock moves after an earnings report is about as predictable as a coin flip. Over the last four quarters, it has had an even split, closing higher the day after earnings twice and closing lower twice, despite beating headline EPS expectations each time. Its moves this year have been significant, closing up 10% after its April 29 report, and down 7.1% after its July 22 report.

Stretching it to the last 16 quarters, Alphabet has closed up seven times and closed down nine times. The average move is 5.2% in either direction.

Why July's beat turned into a sharp drop

Alphabet's earnings report in Q2 2026 looked great on the surface. Revenue was up 24% to $119.8 billion, Google Cloud revenue grew 82% to $24.8 billion, and EPS skyrocketed 294% to $9.11. The company's post-earnings slump makes more sense when you dig a little deeper.

Net income included about $99 billion in unrealized gains, mostly from Alphabet's investments in Space Exploration Technologies and Anthropic, and that caused the huge jump in EPS. These holdings are certainly valuable, but an increase in unrealized gains is much different from an increase in sales. Alphabet's adjusted EPS (without the unrealized gains) was $2.85, which actually missed consensus estimates by $0.04.

Alphabet also raised its 2026 capex guidance to between $195 billion and $205 billion, and management said that 2027 capex will increase significantly. The company ended the quarter with negative free cash flow for the first time in its history since going public in 2004. The heavy spending worried investors and resulted in a sell-off.

What to watch on Oct. 28

There are a few potential swing factors, outside of revenue and EPS, to watch for in Alphabet's Q3 earnings. Any updates to its 2026 capex, as well as early guidance for 2027, could cause a big move, especially as rates have gone up and investors have become increasingly concerned with AI spending.

Free cash flow will give an idea of how manageable Alphabet's spending is. CFO Anat Ashkenazi said it will "remain under pressure" in the Q2 earnings call. How deep in the red it ends up will likely play a role in how the market reacts to earnings. Finally, Google Cloud revenue is a key metric, as it indicates that all the AI spending is turning into measurable sales growth. Ideally, Google Cloud growth will hold around 80%.

All that said, it's best to keep your expectations open. Earnings reports and post-earnings performance are inherently unpredictable. Considering how investors have rotated out of AI stocks recently, I think a decline in Alphabet stock is more likely than a surge post-earnings. However, when you're a long-term investor, what matters is what a company does over a period of years, not right after earnings.

Lyle Daly has positions in Alphabet. The Motley Fool has positions in and recommends Alphabet. The Motley Fool has a disclosure policy.