Goldman Sachs' upgrade of Tesla stock, just hours before the electric car maker revealed it also had tapped the investment bank to underwrite a $1.7 billion stock sale, already has drawn plenty of critics.
One lawyer said it also should draw scrutiny from the Securities and Exchange Commission.
"To start investigating, all the SEC has to do is have a belief that something amiss may have happened," said Andrew Stoltmann, a Chicago lawyer who has pursued dozens of arbitration actions and lawsuits against large financial services firms.
And Stoltmann believes the commission has enough to go on, simply in the timing of the stock sale announcement.
Early Wednesday, Goldman Sachs revealed a bullish upgrade of Tesla stock, to "buy" from "neutral," calling for 22 percent upside and a six-month price target of $250. The bank said it doesn't "believe Tesla shares are fully capturing the company's disruptive potential."
Tesla shares rose at the open Wednesday. But after the market closed, Tesla announced its stock offering would be co-led by Goldman, and the carmaker's shares gave back gains, falling into the red in after-the-bell trading. The shares were up more than 2 percent late Thursday.
Big banks are required to keep a "Chinese wall" separating research divisions from banking teams.
Stoltmann, a self-described "Goldman critic," said he believes Wednesday's roller-coaster ride for Tesla stockholders represents the bank employing a "Swiss-cheese wall" between divisions instead. He's not alone; Twitter lit up with conspiracy theories and accusations after the deal was announced.
Goldman said its dealings were on the up-and-up.
"Our research is independent," a Goldman representative said in an emailed statement. "We followed all of our standard policies and procedures with respect to our research publication on Wednesday."
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And not everyone agrees with the outspoken attorney.
"It's uncommon, but probably not unusual," said one industry lawyer who declined to be named.
The lawyer said that, potentially, the bank's independence between research and banking arms is what ultimately led to the timing surrounding the upgrade and subsequent offering. Further, the bank has a yearslong relationship with Elon Musk's automaker; it isn't as if Tesla became a Goldman client this Wednesday.
The SEC did not respond when CNBC.com sought comment.
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