1. The Situation
Costco is trading near all-time highs while the S&P 500 sells off. Its 63-day rate of change just hit the 99.6th percentile of everything recorded in our database — meaning it has almost never moved this far, this fast, over three months. And yet its short-term volatility is sitting at just the 6th percentile. A near-record price surge, delivered with near-record calm. That combination is rarer than it sounds, and the history of what happens next is more nuanced than any headline will tell you.
2. The Conventional Read
The narrative on Costco is straightforward and, to be fair, well-supported. The business is performing. Q2 fiscal 2026 results (reported March 5, 2026) came in ahead of estimates: revenue of $69.6 billion grew 9.1% year-on-year, EPS of $4.58 beat the $4.55 consensus, and net income hit $2.035 billion — up 13.8% from a year prior. Membership fee revenue grew 14% to $1.36 billion. Digital sales surged 22.6%. Comparable sales rose 7.4%.
The macro backdrop has been increasingly favourable for Costco specifically. As tariff uncertainty has weighed on risk assets since the turn of the year, capital has rotated into defensive and consumer staples names. Costco is the archetype. Its beta is 0.39 — it moves at less than half the speed of the broader market — and its renewal rates at 92.1% signal customer relationships that don't dissolve under pressure.
Analyst consensus sits at a median price target of approximately $1,050–$1,075 from 42 analysts, with the most recent targets from BMO Capital ($1,315) and Telsey Advisory Group ($1,125) set in late March 2026. The bull case: membership growth, 28 new warehouses planned for FY2026, digital acceleration, and potential $500M–$2B tariff refund following a February 2026 Supreme Court ruling. The bear case: P/E above 52x, renewal rate softness (first meaningful decline in years to 92.1%), and competition from Sam's Club and BJ's.
3. What the Percentile Data Shows
As of April 6, 2026, Costco's four-dimension percentile snapshot:
| Dimension | Percentile | Reading |
|---|---|---|
| Extension | 86th | Price historically far above moving averages |
| Momentum | 82nd | Rate-of-change in top quintile |
| Flow | 80th | Money flow indicators broadly positive |
| Volatility | 28th | Near historically low realised volatility |
Individual indicators of note: RSI-14 at 64.2 (90th percentile), RSI-5 at 87.8 (97.6th percentile, short-term overbought), ROC-63 at +19.4% (99.6th percentile — almost never this high over three months), 21-day realised volatility at 13.9% (6th percentile — extremely calm), CMF at -0.031 technically in distribution but at its 82.4th percentile historically.
Composite scores: Flow & Accumulation 69/100, Trend & Momentum 81/100, Risk Profile 62/100.
A composite-only reading labels this "strong uptrend, extended." That same label applies to episodes that saw 8–21% drawdowns and episodes that continued rising 12–15%. The composite is insufficient. The dimensional detail is where the information sits.
4. The Historical Test
We pulled every instance where Costco's extension percentile exceeded 80, going back to 2021: 25 distinct episodes.
Overall forward returns:
| Horizon | Median return | Positive rate |
|---|---|---|
| 21 days | -0.14% | 52% |
| 63 days | +1.6% | 60% |
A 52% positive rate at 21 days looks like a coin flip. But within that cohort, the distribution is systematically determined by one variable.
Split by volatility regime:
| Volatility regime | 21d median | 21d positive | 63d median | 63d positive |
|---|---|---|---|---|
| Low vol (<40th pct) | +1.3% | 72% | +4.2% | 73% |
| High vol (≥40th pct) | -3.8% | 33% | -7.4% | 28% |
In low-volatility extension episodes, Costco showed a 72% positive rate at 21 days. In high-volatility extension episodes, that collapsed to 33%. Today's volatility is at the 6th percentile — firmly low-vol.
5. The Episode Comparison
June 2024 — Extension 89, Momentum 88, Flow 80, Volatility 31 (low) Price ~$848. 63-day return: +0.9%. Orderly consolidation, no breakdown. The stock digested the extension over several weeks before continuing higher.
February 2025 — Extension 87–94, Momentum 96–99, Flow 94–98, Volatility 57–75 (high) Price ~$1,050–$1,078. All four dimensions elevated. 21-day return: -3.3%. 63-day return: -9.1%. The stock fell from $1,078 to approximately $870 as tariff concerns and risk-off sentiment hit growth expectations. The volatility percentile was the warning signal.
March 2024 — Extension 97, Momentum 95, Flow 79, Volatility 35 (low-moderate) Price ~$786. Extension at the 97th percentile — near the top of the database. 21-day return: -6.9%. Even low volatility couldn't absorb extension at that level. There is a threshold above which extension itself becomes the dominant headwind.
January 2026 — Extension 82–89, Momentum 95–97, Flow 93–99, Volatility 64–68 (high) Price ~$964–$983. The most recent prior episode. Pulled back to $960 before recovering. High-vol extension resolved with a sharp reversion, consistent with the pattern.
6. The Discriminator
For Costco, the separator is volatility regime.
Low volatility during extension means the move is happening on low anxiety — patient capital, few forced sellers, no panic buying. That kind of extension tends to resolve gradually: sideways consolidation, then continuation or a modest, orderly pullback.
High volatility during extension means the move is happening with turbulence — hedging, forced selling, sentiment reversals all amplifying any reversion.
Today's combination of 86th percentile extension and 6th percentile volatility has appeared in roughly a third of historical episodes. In those instances, the 21-day forward return median was positive and the positive rate exceeded 70%.
One secondary check: the two episodes that declined despite low volatility (March 2024 most clearly) both had extension above the 95th percentile. Today at 86 is elevated, but not in that danger zone. Price is +7.6% above the 200-day SMA and +3.0% above the 50-day — stretched, but not historically extraordinary.
7. The Fundamental Tension
The bull case: Q2 showed 13.8% net income growth, 9.1% revenue growth, 14% membership fee income growth — the highest-margin line in the business. With a 0.39 beta and 92.1% renewal rates, Costco is the definition of a defensive compounder. Tariff-driven risk-off rotation is an explicit tailwind, and the potential $500M–$2B tariff refund remains an unpriced asymmetric upside catalyst. Analyst targets from BMO ($1,315), JP Morgan, and Telsey Advisory Group ($1,125) all set in March 2026 point to 10–30% upside from current levels.
The bear case: The P/E is above 52x on 3% net profit margins. Renewal rates slipped to 92.1% — the first meaningful decline in years, and structurally pressured as online-acquired members (who renew at lower rates) become a growing share of the base. The stock has moved +19.4% in 63 days, a reading at the 99.6th percentile. That level of price momentum has historically been followed by at least some digestion. The resistance zone at $1,017–$1,044 is directly overhead.
The structural tension: Costco may be the single best-positioned large-cap to benefit from both risk-off macro rotation and value-seeking consumer behaviour. But those tailwinds are already in the multiple. The question is not whether Costco is a good business — it clearly is — but whether the stock can grow into a 52x earnings multiple in an environment where growth could slow.
8. Where We Are Now
Today's profile most closely resembles the June 2024 cluster: 86th–89th percentile extension, elevated but not euphoric momentum, moderately positive flow, historically low volatility. That episode resolved benignly — consolidation without breakdown.
It also resembles the early 2024 cluster (January–February 2024, $680–$725): low volatility, elevated extension, moderate momentum. Those episodes all resolved positively at 63 days, with returns ranging from flat to +7%.
Where today differs from the negative outcomes: the bad episodes of February 2025 and January 2026 had volatility percentiles of 57–75. Today's is 6. That's a fundamentally different risk environment.
Where caution is warranted: price closed at $1,018.55 — right at the lower edge of the $1,017–$1,044 resistance zone (double tops, major swing highs, and minor swing all confluent here). The volume profile shows thin trading above $1,030. Nearest strong support is $956–$984 — approximately 4–6% lower if the resistance triggers reversion. The Risk Profile Score of 62/100 is adequate but reflects the difficult year-long Sortino of just 0.30.
9. What to Watch
The resistance zone at $1,017–$1,044. Not whether it holds or breaks in a single session, but the character of the test. A break above $1,044 on RVOL >1.5 with CMF turning positive = genuine continuation signal. A rejection on declining volume = consolidation scenario.
The volatility percentile. Currently 6. If macro developments push 21-day realised volatility sustainably above 18–20% (percentile above ~40), the risk profile of this episode changes materially — historical patterns are unambiguous about this transition.
Next earnings: July 29, 2026. Two things matter most: whether renewal rates stabilise above 92%, and whether comparable sales hold above 5% as consumers face tariff-driven price pressure. A third consecutive quarter of 13–14% membership fee income growth would be the most powerful fundamental confirmation available.
No prediction. No buy or sell.
Disclaimer
Data as of April 6, 2026. All indicator values sourced from the Flipside Finance pipeline. Percentile lookback window: rolling 365 days. Historical episode analysis covers approximately 1,300 trading days (2021–present). This is not investment advice. Past patterns in percentile signals do not guarantee future price outcomes. Earnings data sourced from Costco's official Q2 FY2026 earnings release (March 5, 2026). Analyst targets sourced from publicly available consensus data as of early April 2026.