Musk had said that production was on track to start in July, but Tesla has often faced delays in getting vehicles to market. Tesla aims to make 5,000 Model 3 sedans per week by the end of this year and 10,000 per week in 2018.
"Expectations on the buy side are that there will be two to three quarters of delays on those sorts of numbers," Rusch said.
Still, Musk displayed a new level of confidence after his announcement, Rusch said. What's really driving Tesla's stock is the future of transportation, he added.
"We have to see how things shake out and how things ramp. There is always a surprise with this sort of thing. But I think this is a very good day for Tesla that they're starting early and feeling confident," Rusch said.
R.W. Baird analyst Ben Kallo, one of the most bullish analysts on Tesla, said the company will face one "good problem" in its production of the Model 3.
"The biggest thing that we look at is the infrastructure needed, you know, to service the cars, to sell the cars and charge the cars as you go from a couple hundred thousand on the road to a million or 2 million on the road over the next two to three years, but that's a good problem to have as they build out their fleet," Kallo said in an interview on CNBC's "Closing Bell."
— The Associated Press and CNBC's Abigail Summerville contributed to this report.