The managed care industry group was Friday’s top performer with a 5% gain, thanks to reports that Humana (HUM) is putting itself up for sale with Aetna (AET) and Cigna (CI) as possible buyers. The news crossed the wires about 1:15 p.m. ET, sending shares of managed care companies higher, some to new highs. Humana made the most spectacular intraday move, closing up 20% in huge volume.