Why most pairs stop working (and what benching means)

A pair is only as good as the relationship between the two companies, and relationships change. Most pairs that once moved together eventually stop doing so.

Common reasons

• One company changes shape — an acquisition, a spin-off, a new product line or a lost one.
• A company-specific shock — litigation, a regulatory decision, an accounting problem — hits one name and not the other.
• The industry shifts and the two businesses start responding differently to the same forces.
• The relationship was never as strong as it looked; a long run of similar moves can happen by chance.

Benching: re-testing every night

PairsCopilot does not assume a pair that qualified once stays qualified. Every night, each pair is re-tested for the two things the strategy depends on: that its gap still tends to come back, and that it comes back fast enough to be useful. A pair that fails either test is benched — it publishes nothing that night — and it publishes again only once it passes.

Separately, a pair whose gap keeps reaching the safety-stop distance is suspended automatically, and only a manual review can bring it back.

Why this is shown publicly

Each pair page shows how many nights the pair has qualified since tracking began and whether it is qualified, benched or suspended now. Seeing pairs fail the test is part of judging whether the process is strict.