Full-time trader Erik Smolinski got a head start on investing. While still in high school, a teacher encouraged him to put the money he earned from odd jobs into the stock market. He started early and never stopped.

Today, in his early 30s, the Marine veteran and full-time trader considers himself financially independent and has a seven-figure net worth, which Business Insider verified by reviewing screenshots of his trading account.

Smolinski believes wealth-building doesn’t require complicated strategies — just a solid grasp of a few fundamentals.

Here are three changes he says all investors should focus on this year if they want to build wealth.

1. Save 10% more

Building wealth starts with keeping more of what you earn.

“Find a way to save 10% more per month,” Smolinski told Business Insider. “That’s a perfect starting goal for most people.”

He emphasized that small lifestyle changes can make a meaningful difference over time.

For example, “rather than having two subscriptions — one to Netflix and one to Disney Plus — get rid of one and just divert the rest of that into your savings,” he said. Keep in mind that “the more aggressively you delay gratification upfront, the less you have to delay it overall.”

2. Think about what the world will look like in three to five years

Smolinski encourage all investors to step back and ask a simple question: What do you think the world will look like a few years from now?

“I’m typically a growth-factor guy,” he said. “I’m typically bullish. I generally think people are going to become more innovative, companies are going to become smarter, and more value will be created.”

From there, he thinks about where that value is likely to be concentrated and adjusts his investments accordingly.

“Make sure your holdings reflect what you think the world might look like in three to five years,” said Smolinski, adding that, personally, he’s betting on AI.

3. Increase your income

Saving matters, but Smolinski says growing income is just as important, especially early on.

“That’s the other thing everybody should be focused on until they start getting closer to their financial goals: How can I earn more money?” he said.

Higher income creates more flexibility to save and invest, speeding up the wealth-building process.

Smolinski suggests two strategies for boosting your income: Pursue a raise within your day job or start a side hustle.

The more aggressively you save and the more aggressively you grow your income, the sooner you’ll hit financial independence, and that’s when “you get to start doing the cool stuff,” he said.

“That’s when you get to spend your time, energy, and money on the stuff that you actually value.”