Several Big Cap 20 stocks have recently broken out of bases, but are still within buy range, or are building new bases and could be good additions to a watch list. Alexion Pharmaceuticals (ALXN) has pulled back and is within the 5% buy zone. The stock broke out of a cup-with-handle base Oct. 23 with double the usual volume. Going back to Q4 of 2010, the slowest rate of year-over-year quarterly growth was 38%.