Shares of Indian solar companies, including Waaree Energies and Premier Energies, experienced significant gains following a U.S. decision to impose substantial tariffs on solar panel imports from Southeast Asia.

The United States has imposed new duties of up to 3521% on imports of solar panels from four Southeast Asian countries, Bloomberg reports. The tariffs announced on April 21 are the culmination of a year-long trade investigation.

U.S. trade officials finalized steep tariff levels on most solar cells from Southeast Asia, a key step toward wrapping up a year-old trade case in which American manufacturers accused Chinese companies of flooding the market with unfairly cheap goods.