: a person who takes part in or becomes enthusiastic about something only when it is popular or fashionable
… ugly performances through December and the first half of January caused more than a few bandwagoners to jump ship … Kevin Greenstein, New York Sun, 6 Feb. 2008
… Hawks fans bellyached about the affluent bandwagoners who are scooping up tickets … Dan McNeil, Chicago Tribune, 28 May 2010
Though they are sometimes derided as shameless bandwagoners who leap into and out of stocks with abandon—increasing volatility in the process—it's not always a fair charge: Some momentum investors actually hold stocks for relatively long periods. Melanie Warner, Fortune, 9 Dec. 1996
The original innovators have moved on, and all that remains are bandwagoneers pumping out an astounding amount of identical-looking product … Patricia Calhoun and Justin F. Farrar, Houston Press, 31 Aug. 2006