The stock market soared on Monday, with major benchmarks finishing higher by 1% or more following a weekend that featured somewhat less devastation than many had feared. Hurricane Irma spent most of the weekend working its way toward and up the Florida coast, but a change in its course shifted some of the focus from major metropolitan areas on the eastern side of the state. At the same time, geopolitical problems showed signs of calming down as well, with a lack of provocative news out of North Korea. Even with markets sharply higher, some stocks stood out with still more impressive gains. Teva Pharmaceutical Industries (TEVA 0.63%), MercadoLibre (MELI -1.01%), and XL Group (XL) were among the best performers on the day. Below, we'll look more closely at these stocks to tell you why they did so well.

Teva gets a new leader

Shares of Teva Pharmaceutical Industries climbed nearly 20% after the drug company said that it had selected a new chief executive officer. Kare Schultz will take over as CEO of Teva, bringing extensive experience that includes a stint as CEO of drug-making peer Lundbeck. Teva board chair Sol Barer pointed to Schultz's "keen knowledge of the generic and specialty drug markets" as being of particular value to the company, which sports businesses in both markets. Interim CEO Yitzhak Peterburg will stay in the role until Schultz can formally join Teva, at which point the new chief executive will face the uphill battle of getting Teva's positive momentum re-established.

Teva Pharmaceutical logo.

Image source: Teva Pharmaceutical Industries.

MercadoLibre rides Latin American momentum higher

MercadoLibre stock gained 10% in the wake of favorable moves in several key Latin American stock markets. In particular, stocks in Brazil continued their sharp advance from last week, rising another 2% on growing optimism that lower interest rates in the emerging market nation could spur further economic growth that in turn will prompt more shoppers to spend money online. MercadoLibre has worked hard to prepare for a full recovery in Latin America's economies, and if Brazil and its neighbors can demonstrate their staying power, then the evidence should show up in MercadoLibre's fundamental business metrics in the quarters to come.

XL breathes a sigh of relief

Finally, shares of XL Group gained 5%. The insurance company was one of many that rebounded at least somewhat following Hurricane Irma's passage through Florida over the weekend, as declines of more than 10% in the days leading up to landfall reflected the nervousness that investors felt about the storm's potential impact. Despite avoiding worst-case scenarios, this quarter promises to be a tough one for XL and its peers, because combined costs from Hurricanes Harvey and Irma could end up rivaling what Hurricane Katrina cost more than a decade ago. Investors will have to wait several weeks before getting a final toll on the devastation across the region.