Is the 'Sell in May' Market Cliché Still Relevant for Bitcoin and Equities?

“Sell in May and go away” is the idea that stocks reliably underperform between May and October, and it describes a market that might no longer exist.

Bloomberg Intelligence data shows the S&P 500 ETF has closed the May-October period in positive territory in 25 of the last 33 years, with only one negative summer stretch in the past decade.

Bespoke data cited by Bloomberg shows the cumulative return from holding SPY is only in May-October since the ETF's 1993 debut, at roughly 171%. That is real money, just considerably less than the 731% earned by staying long only in November-April.

Despite the seasonal performance difference, the cliché that May automatically means sell does not hold.

The logic behind the old saying is that corporate earnings slow, trading desks thin out, and investors rotate into cash or bonds until autumn. That playbook worked well enough for decades, built for a market where institutional money moved slowly, and risk appetite followed a predictable rhythm.

Bitcoin has spent two years building direct plumbing into traditional portfolio flows. Data from Farside Investors shows that US spot Bitcoin ETFs pulled in roughly $1.5 billion between Apr. 17 and 24, and cumulative net inflows have reached approximately $58.3 billion. That market structure has folded Bitcoin into the same risk appetite machinery that drives equities, giving BTC direct exposure to whatever keeps institutional investors willing to hold.

When institutional money does not reflexively de-risk into summer, BTC avoids one of the psychological headwinds that have historically hit speculative assets in May. The Federal Reserve's own research has flagged that crypto ETP bid-ask spreads are broadly comparable to those of similarly sized equity ETFs and ETPs, and has argued that NAV premiums in crypto funds warrant monitoring as a measure of how interconnected crypto and equity markets have become.

The case for Bitcoin entering summer with fewer headwinds depends almost entirely on what the next six weeks of data deliver. The Fed's Apr. 28-29 meeting produced a policy decision and a press conference by Fed Chair Jerome Powell on Apr. 29. The Bureau of Economic Analysis releases first-quarter GDP and March PCE on Apr. 30. April payrolls land May 8, April CPI arrives May 12, and the FOMC minutes from the April meeting come May 20, and the next full Fed meeting runs June 16-17.

That sequence either confirms that “Sell in May” has lost its macro rationale or rebuilds it this time. Atlanta Fed's GDPNow put first-quarter growth at 1.2% as of Apr. 21, compared with the official GDP of 0.7% for the fourth quarter of 2025. March CPI came in at 3.3% year-over-year, core CPI at 2.6%, and the energy index jumped 10.9% month-over-month. February PCE was 2.8%, and core PCE was 3.0%.

Cleveland Fed nowcasts as of Apr. 28 put April CPI at 3.56% year-over-year and April PCE at 3.60%. The March Fed SEP raised both 2026 PCE and core PCE medians to 2.7%, and 17 of 19 participants marked inflation risks as skewed to the upside. Cross-market conditions as of late April are contained. The 2-year Treasury yield was 3.78%, the 10-year was 4.31%, the VIX was 18.02, and BTC was in the $76,000 zone.

BlackRock's spring outlook frames the current setup as a mild stagflation trade-off, in which the Fed stays on pause and moves toward gradual easing only if inflation keeps cooling or growth moderates. If April PCE and May CPI print close to or softer than current nowcasts, and April payrolls cool without triggering recession fears, the Fed can credibly stay data-dependent.

That keeps the 2-year yield anchored in roughly the 3.65%-3.85% range, VIX below 20, and SPY grinding sideways to higher. In that backdrop, ETF inflows become the marginal driver for Bitcoin. Institutional allocators who built Bitcoin positions through IBIT and peer funds have no obvious seasonal reason to reduce exposure.

Bitcoin can hold a $72,000-$85,000 range into the June Fed window. If core inflation prints softer than feared while payrolls miss cleanly without alarming growth data, markets can re-price a clearer easing path for the second half of 2025.

If PCE or CPI re-accelerate beyond nowcasts, if April payrolls surprise to the upside, or if Powell makes clear at the Apr. 29 press conference that the bar for cuts is higher than markets anticipate, Treasury yields back up. A 2-year yield pushing toward or above 4% tightens financial conditions, compresses equity multiples, and removes the liquidity backdrop that has supported Bitcoin's ETF-era rally. In that environment, BTC trades as a high-beta macro asset; a retreat into the $65,000-$72,000 range becomes plausible, pulled lower by the same risk appetite that had been carrying it higher.

The Philadelphia Fed's Anxious Index put the probability of a second-quarter GDP decline at 20.9% in the first-quarter survey, a level elevated enough to keep recession risk alive as a tail risk. If GDP surprises to the downside while inflation stays sticky, the Fed faces a classic stagflation bind in which neither cutting nor hiking resolves the problem. That stagflation bind is the version that actually bites. Bitcoin has absorbed Wall Street's infrastructure and inherited its constraints along with its capital. Seasonal folklore has always been a proxy for the idea that summer is when macro imbalances get priced in, liquidity thins at the margin, and investors reassess what they want to own. The next six weeks will test if the macro regime that carried Bitcoin to record highs can survive inflation data.