Shares of the San Jose, Calif., company at last check rose 17% to $171.78 and were up 77% year to-date.
The company reported earnings of $2.18 a share, up from $1.24 a year ago and beating the FactSet consensus estimate of $2 a share.
Revenue totaled $327.8 million, up from $277.6 million and beating Wall Street's called for $324.7 million .
Synaptics posted record GAAP and adjusted gross margin in the June quarter, Michael Hurlston, president and chief executive, said in a statement.
In addition, he said, the company "made progress throughout the year tilting our portfolio toward our internet-of-things products, which now represent more than 50% of our overall revenue."
Looking ahead, Synaptics said it expected first-quarter revenue of $355 million to $385 million. The FactSet consensus calls for revenue of $363 million.
Analysts responded favorably to the company's results. Susquehanna analyst Christopher Rolland raised his price target on Synaptics to $180 from $150 while keeping a positive rating on the shares, according to the Fly.
Rolland said Synaptics was in the "middle innings" of executing a bona-fide turnaround, and these results are yet another point of confirmation.
Craig-Hallum analyst Anthony Stoss lifted his price target to $175 from $160 and kept a buy rating on the shares.
Synaptics's results and guidance were well above Wall Street's estimates, he said, and the company surpassed its gross margin and operating margin goals one year early.
Needham analyst Rajvindra Gill raised his price target to $220 from $200 while affirming a buy rating. The analyst cited the company's "significant" beat-and-raise fourth-quarter results, with gross margins of 57.5% topping the management's long-term plan as well as the consensus estimate.
Gill added that Synaptics's earnings have more than doubled (up 120%) over the past three fiscal years and the company has been "one of the best performers" in the PHLX Semiconductor undefined Index with a 51% year-to-date advance.