NEW YORK CITY, New York: As 2025 draws to a close, one viral TikTok trend is helping people refocus on their goals, from fitness to finances. Called "The Great Lock In," the challenge encourages participants to spend the final four months of the year — from September through December — locking in on self-improvement and finishing the year strong.

While many users focus on wellness goals like exercising more or eating healthier, experts say the same idea can be a powerful tool for financial growth.

There are no formal rules. The term "lock in", popular on social media, means to focus intensely on something. "Something I like about this particular trend is that it's like New Year's resolutions' little sister," said Lindsay Bryan-Podvin, financial therapist and founder of the Mind Money Balance podcast and blog.

For Julissa Mercedes, 28, a finance professional from San Diego, the challenge is about building security. Her goal: saving US$2,500 for an emergency fund. "Having some liquid cash will make me feel a little bit safer," she said. Mercedes has also set three other goals — making a new friend, creating a morning routine, and picking up a hobby.

The Great Lock In is meant to revive resolutions that might have fizzled out earlier in the year. For those who started 2025 hoping to pay off debt or cut spending, the challenge can serve as a fresh restart.

"I think that's appealing to a lot of people who are just tired of feeling stuck and like they haven't been able to make any progress," said Ben Markley, personal finance educator and host of Sketchy Advice by YNAB, a budgeting podcast.

Experts say the key to making the trend work financially is to treat it less like a sprint and more like a reset.

Review your finances: Bryan-Podvin recommends starting by checking your bank accounts, understanding your income and expenses, and reassessing your financial goals.

Set realistic targets: Markley warns that social media challenges can inspire unrealistic expectations. "A lot of people can't sustain that at all, so they drop off," he said. "Or, they do sustain it, but then they go back to their normal life after the challenge."

Build habits, not pressure: Focus on small, repeatable habits — like cooking more often to save on takeout — and use tools such as habit-tracking apps or phone reminders to stay consistent.

Find community: Social media can also be a source of accountability. Mercedes shares her own progress on TikTok, saying it keeps her motivated. "Seeing that people are still watching and keeping up with my content makes me feel like they're part of the journey too," she said.

Reflect on your money mindset: Markley suggests assigning every dollar a job — being intentional with spending and reviewing finances regularly. "You're making sure your money goes toward the things you need and the things you care about," he said.

And if the challenge doesn't stick? That's fine, too. "You can find something else that works," Markley said. "It's no reflection on your character if you don't pull off The Great Lock In."

Not every viral challenge fits everyone, experts say, but if it helps you save, spend, or live more intentionally, it may be worth locking in for the rest of the year.