Tower stocks have performed well year-to-date, benefiting from a combination of the reversal in the 10-year treasury rates, broader investor interest, strengthening operating performance, and now the potential for a new wireless entrant to take the place of Sprint (S) as a fourth national wireless competitor, Citi analyst Michael Rollins tells investors in a research note. The analyst continues to like the fundamental operating environment and sees room for average site leasing growth to improve through 2020. However, intrinsic valuations remain elevated on tower cash gross profit multiples and are at the higher-end of transaction ranges that were established for larger, strategic acquisitions, adds the analyst. He raised his price target for Neutral-rated American Tower (AMT) to $231 from $205, for Neutral-rated Crown Castle (CCI) to $144 from $136 and for Buy-rated SBA Communications (SBAC) to $270 from $227.