It's been a volatile few months for Facebook shares, and one strategist says the stock is in a precarious position in the middle of an important week for the company.

The social network's chief operating officer, Sheryl Sandberg, was testifying before the Senate Intelligence Committee on Wednesday about election-related manipulation on the platform ahead of U.S. elections this year. Another technology executive, Twitter CEO Jack Dorsey, was also testifying about similar abuses.

"This chart looks very, very dicey right now. The bounce we've seen since its 21% July decline (its post-earnings report decline) was a feeble one," Matt Maley, equity strategist at Miller Tabak, said in an email to CNBC on Tuesday.

"How [Facebook] trades after we come out of the congressional testimony is going to be very, very important," Maley added Tuesday on CNBC's "Trading Nation."

The levels investors should watch are $170 and $171, Maley said. Facebook was more than 1 percent lower on Wednesday, right around the $169 per share mark, after falling nearly 3 percent Tuesday. Wall Street firm MoffettNathanson downgraded the stock to neutral from buy, citing a forecast slowdown in revenue growth coupled with mounting regulatory scrutiny.

Although the stock bounced from its year-to-date low in March, Maley pointed out that the name has posted a "lower high," along with a "lower low" on the chart, suggesting the price action has been weak.

Facebook shares are trading firmly in a bear market — down 22 percent from their high in July, when the stock crashed on its earnings report — even after it managed to claw back its Cambridge Analytica scandal-fueled losses.

"If the stock can hold here, we're OK, but any break of that $170, $171 level is going to be a problem," he said.

Slowing growth has already been priced into the stock to some degree, said Gina Sanchez, CEO of Chantico Global. The stock's forward price-earnings ratio has fallen to about 22 times, from a little more than 28 times at the beginning of this year.

"That, coupled with the question around deregulation, the question of — can Facebook self-police?" creates a meaningful headwind, Sanchez said Tuesday on "Trading Nation."

Facebook shares were down 1.1 percent Wednesday.