COST

Historical Beat Rate and Post-Earnings Drift

Costco Wholesale (COST) has beaten earnings estimates in 6 of the last 8 reported quarters, a 75% beat rate, with an average surprise of just 0.4%. That 0.4% figure is small enough that a “beat” in this name can be little more than rounding against the consensus. More importantly, the average 5-day price move in the five trading days after the report is -1.51%, classified as a down drift.

Stated plainly: even the beat/miss label has not governed the stock well. The May 28, 2026 report saw COST miss by 1.4% (actual EPS $4.93 versus estimate $5.00), and the stock fell 3.91% the next day and was down 2.3% over the following five sessions. By contrast, the December 11, 2025 report beat by 1.6% (actual EPS $4.34 against estimate $4.27), yet the five-day drift was -3.04%. The September 25, 2025 quarter delivered a 1.2% beat ($5.87 versus $5.80) and still produced a five-day return of -2.81%. Only the March 5, 2026 report, a 0.7% beat ($4.58 versus $4.55), showed positive follow-through, gaining 1.58% the next day and 2.11% over five sessions.

Options-Flow Dynamics Around the September 24 Report

COST next reports after the close on September 24, 2026, with the consensus EPS estimate at $6.51. At the current snapshot price of $951.89, the stock sits just under its 50-day EMA of $958.42, while the RSI reads 51.4—essentially neutral. That price setup gives the options market few directional tells on its own, so short-dated implied volatility becomes the main item to watch.

Options flow ahead of the print will typically concentrate in weekly expirations straddling the report. The implied move priced into those straddles can be compared with the realized one-day post-earnings reactions most recently observed: -3.91% (May 28, 2026), 1.58% (March 5, 2026), 0% (December 11, 2025), and -2.9% (September 25, 2025). If the options are pricing a move below the recent average magnitude, sellers are treating the report as benign; if they are pricing above it, the market is paying for event risk. Skew matters as well—whether put or call premium is catching the majority of flow—because directionless neutral readings like the current RSI can hide asymmetric hedging around a large event.

What a Disciplined Trader Watches

A disciplined approach here starts with the fact that the 5-day post-earnings drift has been -1.51% over the last eight quarters and negative in three of the last four quarters. That is a specific historical pattern, not a forecast. The next test is whether the stock follows the same path or diverges after the September 24, 2026 report.

Technically, $958.42 is the 50-day EMA reference and $951.89 is the current price, so the initial setup is slightly below that intermediate average. The EPS bar is $6.51, versus the 0.4% average surprise of the last eight reports, so the unofficial consensus does not imply huge variance relative to history. A trader can watch how price behaves relative to the EMA in the sessions immediately following the release, track whether the five-day drift begins to extend to the -1.5% to -3% region observed recently, or whether the March 2026 pattern (+2.11% five-day) repeats.

For a deeper dive into how institutional models are positioned ahead of the September 24 print, explore the full institutional verdict.