Tesla said Wednesday it is offering $1.6 billion in convertible senior notes in an underwritten registered public offering.
The company plans to use the proceeds from the sale to fund its "Gigafactory and the development of its 'Gen III'" mass market vehicle, the company said in a press release.
Tesla plans to build its Gigafactory on anywhere from 500-1,000 acres of land in New Mexico, Arizona, Nevada or Texas, according to the company's 10-K. The company expects the factory to run at full capacity in about 2020, employing 6,500 people and producing around 500,000 cars.
(Watch: Tesla shares go into overdrive)
Executives predict the Gigafactory will cut the cost of producing the lithium ion batteries that power its cars by 30 percent.
The company plans to pay about $2 billion of the total $4-5 billion needed to build the factory.
Goldman, Sachs & Co., Morgan Stanley, J.P. Morgan and Deutsche Bank Securities are all helping to underwrite the offering.
Tesla shares have been on a tear, climbing to just below $260 in after hours trading on Wednesday. Analyst Adam Jones at Morgan Stanley upgraded his price-target for the electric car maker from $153 to $320 this week.
Apart from the Model S and the upcoming "Gen III," CEO Elon Musk and his team have said they are already working on an SUV-crossover vehicle called the Model X.