Deutsche Bank puts Sell in May back on trial. And finds it guilty of little more than luck

Deutsche Bank says the classic "Sell in May and go away" trade has no reliable edge: on STOXX Europe 600 data since 1987, it delivered 9% annualized versus 7.4% for buy-and-hold, but underperformed in 25 of 39 years and owes most of its outperformance to 1998, 2001 and 2002. The strategy also weakens with bonds and performs worse in the U.S., where the cash version returned 9.3% annualized versus 10.4% for buy-and-hold since 1973. The bank’s message is to ignore seasonality and focus on fundamentals.

Analysis

This is less a dismissal of seasonality than a reminder that positioning regimes matter more than calendar effects. A broad “Sell in May” narrative can still create self-fulfilling flows into defensives, duration, and low-volatility factors, but the edge is likely concentrated in very narrow macro windows: late-cycle growth scares, liquidity squeezes, or rate shocks. In a normal tape, that rule is just a crowded expression of risk aversion with weak standalone signal quality.

The more interesting second-order effect is on factor leadership. If investors rotate out of equities mechanically, the implied beneficiaries are not just cash and sovereign bonds, but also quality, minimum-vol, utilities, and staples — yet those trades are usually expensive by May because everyone owns them for the same reason. That makes the better expression a relative-value pair, not an outright de-risking bet. The article also implies that bond returns only help when rates are stable or falling; if yields back up over summer, the “park it in bonds” leg becomes the hidden source of underperformance.

For markets, the key catalyst is not the calendar but macro dispersion: inflation prints, central-bank rhetoric, and earnings revision breadth over the next 4–12 weeks. If growth data stays firm and rate cuts get deferred, equities can continue higher through summer and punish seasonality shorts again. The contrarian takeaway is that the market may be underweight how much of this trade is now a stale behavioral meme rather than an investable edge — but consensus may still overestimate the protection offered by duration if bond volatility rises alongside equities.

Key Decisions for Investors

• Do not run a blanket May-September equity de-risking trade; instead, keep core longs in cyclicals/quality and avoid paying up for crowded defensive rotation.
• Pair trade: long SPY / short IEF over the next 6-10 weeks if inflation and growth data stay resilient; seasonality fails hardest when bond returns are weak and equity earnings revisions remain positive.
• Relative-value idea: long XLP or XLV vs short XLU into early summer only if defensive valuations reset; otherwise avoid chasing the usual seasonal hideouts after they have already re-rated.
• Use sell-off days to buy upside via 2-3 month call spreads on SPY or QQQ rather than shorting outright; the risk/reward is better if the market keeps grinding higher on de-risking skepticism.
• If you want a seasonal hedge, size it as a tail hedge, not a base case: buy put spreads on IWM or high-beta baskets for June-August, where the payoff is best if the tape turns risk-off, but premium decay stays manageable if the regime stays constructive.