Those stocks, given their size and weighting in the benchmark stock indexes, masked the severity of the S&P problems last year. Facebook Inc. FB, -0.01% gained 34% in 2015, Amazon Inc. was up 118% AMZN, -0.15% Netflix Inc. NFLX, +0.12% returned 135%, and Google Inc. parent Alphabet GOOG, -2.32% picked up 47%. By comparison, the S&P 500 declined 0.7% in 2015.