With the number of preorders for the Model 3 now exceeding 400,000, Tesla Inc. must rapidly scale production if it wants to deliver the vehicles in an acceptable time frame. The car maker is turning to the junk bond market for help with financing the expansion.

Tesla today announced plans to sell about $1.5 billion worth of debt in the form of unsecured senior notes, a departure from previous funding rounds. The company usually prefers to raise capital by selling stock. It most recently raked in $1.2 billion through a May offering.

One potential explanation for the choice to take a different route is that Tesla wishes to avoid diluting investors’ stakes any further. The company has seen its share price climb 67 percent this year, which would offset the impact of any stock sale to a large extent, but Elon Musk and the leadership team apparently believe that raising debt would sit better with Wall Street.

It may prove to be a wise decision in view of the bets made against Tesla by prominent short-sellers such as David Einhorn. Last week, Einhorn warned that the company’s high burn rate could cause financial difficulties further down the road. The upcoming bond sale should give Tesla more breathing room in the next few quarters.

According to Reuters, the car maker had over $3 billion on the balance sheet as of June, compared with $4 billion in the previous quarter and $3.25 billion a year earlier. Tesla forecasts that expenditures will pass $2 billion in 2017 as it works to expand production of the Model 3 (pictured).

Tesla expects to manufacture 5,000 of the sedans every week by the end of 2017 and double that in 2018. Alongside its efforts to scale vehicle production, the company is also pursuing several other projects, including the development of a crossover SUV dubbed the Model Y. It’s set to be based on the same architecture as the Model 3. 

Then there’s the work being done by SolarCity on the renewable energy front. Since its acquisition by Tesla last November, the business has won a contract in Australia to build what is set to become the world’s largest energy storage system. Tesla assumed over $3 billion in liabilities as part of the acquisition, and Business Insider estimates that the forthcoming bond sale will bump the tally past $4.5 billion. 

Image: Tesla