"Timing the market" isn't just the domain of day traders. If you're hoping to buy in at a low price and sell before a big drop, you're a market timer. But in your attempt to maximize your ROI, long-term, you’ll end up underperforming.
Whatever the reason, a second job is often the most sensible solution for solving a serious financial problem. However, before you take on another role, consider whether it’s going to be the difference maker that you need it to be.