The stock is on pace for its best quarter since the third quarter of 2013.

Tesla shares finished the day Wednesday up 3.74%, reaching a record closing price of $393.15, surpassing intraday highs reached when CEO Elon Musk sent his infamous "funding secured" tweet in August 2018 . Today's gains bumped the electric car-manufacturer's market cap up to $70.9 billion.

The company was expected to reduce labor costs and increase profit margins at the facility, but Bloomberg reported Wednesday that the company is considering cutting the price of its China-built Model 3 sedans by 20% or more. Progress at the plant has nonetheless been a hopeful sign for a company that has historically missed forecasts for start of production.

In November, Musk announced plans for the company's fourth gigafactory in Berlin. Tesla sales have increased in European countries throughout the first three quarters of 2019, despite a slowdown in the overall market for new cars in the region.

Building a factory there could help Tesla avoid the complexities of exporting its cars from the states to Europe, and could help it avoid uncertainty around trade and tariffs. In a third-quarter update, Tesla said it plans to produce its already-popular Model 3 electric sedans and forthcoming Model Y, a crossover SUV, at the European factory.

In March, Musk unveiled the Model Y, which will cost between $39,000 to $60,000, and he told investors on the third-quarter earnings call in October that the company is ahead of schedule in rolling the vehicle. The vehicle could debut as early as the first quarter of 2020. A CFRA research report on 2020 automotive outlook published last week had positive outlook on the Model Y.

"Of the 25 new EV models expected to debut in the U.S. in 2020, we think sales of most will flop with the Tesla in our recent report, Automobiles: ElectricModel Y and Ford Mustang Mach-E SUVs being notable exceptions," the report read.

However, some investors are weary that a federal electric vehicle tax credit that benefited Tesla owners in the past will expire at the end of the year. A bill proposed in Congress earlier this year would extend the credit for some manufacturers, including Tesla, but the Dec. 31 deadline looms.

"We think TSLA's relatively attractive combination of price and range give it an advantage over peers in EVs although increased competition and the impending expiration of its federal EV tax credit are headwinds," read a November note from CFRA analyst Garrett Nelson. "Its Autopilot autonomous vehicle (AV) technology has also shown promise."

--CNBC's Lora Kolodny contributed to this report.