Wall Street is always looking for an edge. For SpaceX, that means tracking Starlink subscriptions.

Starlink is SpaceX's space-based broadband product, which ended the second quarter with about 12 million subscribers -- roughly double the number it had a year ago.

More growth is expected, and predicting that growth can help analysts and investors project a third-quarter earnings beat or miss.

KeyBanc analyst Brandon Nispel tracks Starlink app downloads and Google search traffic and believes SpaceX added about 1.8 million new subscribers.

Deutsche Bank analyst Edison Yu uses data from Idem Est Research & Advisory, and expects to see the quarter-end subscriber number up about 1.5 million, or about 13%, from the second quarter.

That should be enough to hit Wall Street revenue estimates -- assuming stable pricing. Analysts project $4.8 billion in quarterly Starlink revenue -- up 12% from about $4.3 billion in the second quarter.

SpaceX will likely report third-quarter numbers in early November. Its first-ever quarterly report in August was much better than expected and helped arrest stock declines that followed its record-setting June IPO.

Overall, Wall Street projects third-quarter revenue of $12.9 billion, up from $7.8 billion in the second quarter. Starlink is growing, but the majority of sales growth is coming from SpaceX's AI business. That segment is expected to generate sales of about $6.4 billion, up from second-quarter sales of $2.6 billion.

SpaceX stock was up 0.4% in premarket trading at $157.12, while S&P 500 and Dow Jones Industrial Average futures were up 0.2% and 0.4%, respectively.

SpaceX stock fell a sharp 4.2% on Tuesday. Profit-taking was as good a reason as any to blame for the decline. Coming into Wednesday trading, the shares were still up about 6% over the past month.