What makes a good share buyback? Barron's cites four factors: i) Shares are in a downtrend. ii) It's a long-term strategy and not a short-term fix ( = >1% share count reduction/quarter). iii) Shares are cheap based on price-to-book. iv) The company has a rising dividend. The stocks that pass the test? Wellpoint (WLP), Seagate (STX), Western Union (WU) and AT&T (T).