It was a classic case of "what goes up must come down" for Rocket Lab Corp (RKLB) on Tuesday. After a strong 10% rally during the day, the company dropped a bit of a bombshell after the bell: it filed to potentially sell up to $1 billion worth of its own stock.

Investors, as they often do when a company announces it's about to flood the market with new shares, didn't take it well. The stock promptly reversed course, falling more than 5% in after-hours trading.

Here's the deal. Rocket Lab entered into what's called an equity distribution agreement. That's a fancy way of saying the company can now sell its common stock periodically, up to that $1 billion ceiling, whenever it decides the time is right. It's not a single, immediate sale, but it's a big number that signals the company is looking to raise a significant amount of capital.

So, what does a space company need a billion dollars for? According to the filing, the money is earmarked for the usual corporate suspects: funding future growth, potentially buying other companies, and covering general expenses and working capital. It's a broad mandate, which is typical for these kinds of filings. The company ended last year with a healthy war chest of about $828.7 million in cash, so this would represent a major addition to its balance sheet.

The timing, however, is what made the market flinch. The stock had just closed at $78.59, up over 10% on the day. The after-hours drop to around $74.42 wiped out more than half of that gain in a matter of minutes. It's a stark reminder that in the stock market, good news can be fleeting, especially when it's followed by news of dilution.

For investors watching from the sidelines, the mechanics are straightforward. If you want a piece of Rocket Lab, you buy the stock directly through a broker. If you prefer a less concentrated bet, you could look for an ETF that holds industrial or aerospace companies, which would give you exposure to Rocket Lab alongside its peers. But after Tuesday's rollercoaster, you might want to buckle up.