Cycles are not periodic. Post-war US expansions have run from one year to more than a decade, and they do not die of old age; they end when something breaks, usually policy tightening, a credit event or a supply shock.
The tradable content is in the sequencing. The curve typically steepens early in an expansion, flattens through the middle, inverts late, and steepens violently into the downturn, while credit spreads and the credit-cycle follow a related but lagged path.
Example: over one full cycle the twos-tens spread runs from plus 250 basis points at the trough, to zero at the peak of the hiking cycle, to minus 80 late, then back to plus 150 as the easing cycle begins.
Related: recession, credit-cycle, twos-tens, nber-dating, output-gap