The common feature is that the outcome is determined by a process with a timetable rather than by general market direction. That makes returns relatively uncorrelated in normal conditions and highly correlated in crises, when deals break and financing disappears together.
Sub-strategies include merger-arbitrage, distressed debt and restructurings, spin-off investing, and activist positions where the investor creates the event themselves. Each requires legal and documentation work as much as financial analysis.
Position sizing dominates because payoffs are asymmetric: a deal that closes returns a few percent, while a deal that breaks can cost twenty or more. Event books are usually diversified across many situations for exactly this reason.
Related: merger-arbitrage, distressed-debt, hedge-fund, convertible-arbitrage, rights-issue, deal-spread