The 2 scenarios when you should refrain from making changes to your investments

There are times when it may make sense to update your investment portfolio. Maybe your investing goals and risk tolerance have considerably changed, an event has occurred that reduces your need for capital appreciation (like a big inheritance) or you suddenly need access to your investments in the near future (three or so years).

Beyond these few exceptions, however, experts generally advise investors to leave their portfolios alone and hold for the long term. And, it's especially a bad time to make changes to your investments under two specific conditions.

It's easy to worry and feel like you need to get your money out of the market whenever it takes a nosedive. However, market downturns, and volatility in general, can be the worst time to change course. These are actually the moments when you need to hold onto your long-term investment strategy and ride out the storm.

"The short-term fluctuations in the market, which loom so large to investors, have little to do with the long-term accumulation of wealth," says Tony Molina, a CPA and senior product specialist at Wealthfront. "Our advice for worried or anxious investors stays the same no matter what: Do nothing."

To avoid reacting to market fluctuations, refrain from looking at your portfolio often. It's a natural instinct to want to immediately respond to a loss in value, so skirt around that knee-jerk reaction by checking up on your investments as little as possible.

Using a robo-advisor is an easy and affordable way to be hands-off with your investing approach. The best robo-advisors offer low-cost diversification and will automatically adjust your investments regularly, also known as rebalancing, so you can rest assured your portfolio is being taken care of. Select reviewed 22 different platforms and narrowed down our top five picks:

• Best overall: Betterment
• Runner-up: Wealthfront
• Best for making a large deposit: Charles Schwab
• Best for women: Ellevest
• Best for extra investing perks: SoFi Invest®

You can read our methodology below for more information on how we chose the best robo-advisors.

Target date index funds are another option for investors who want to be hands off. With a target date fund, you indicate your target retirement date and those who manage your fund will restructure it so that your investments get more conservative, or less risky, the closer you get to that date.

Ivory Johnson, a CFP and founder of Delancey Wealth Management, advises that it’s generally a bad idea to make a major financial decision like changing up your investments when you’re angry or emotional about something.

Such circumstances may entail a death in the family, a broken relationship or a job loss. "Sometimes it makes sense to take a deep breath and regain your composure," Johnson says. On the other hand, an emotional time could also mean when you are feeling deliriously overjoyed about something.

In either instance, a state of sadness or being on a happy high can lend itself to impairing our judgement and ability to reason. These emotions mixed with investing may trigger rash decisions to suddenly sell a stock or overconfidence to buy a stock when our investments are better off left alone.

Investors should generally refrain from altering their investments, especially during market downturns when we may feel rushed to make a change and during emotionally heightened times when our decision-making abilities are clouded. Instead, take these moments to step away from making any important financial moves that could cause more harm than good.

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To determine which robo-advisors offer the best services for investors, Select reviewed 22 different platforms. We then narrowed down our top picks by considering the following factors:

• Account minimums
• Account, advisory, trading and fund fees
• Investment vehicles offered
• Selection of investments
• Educational tools and resources
• Customer support
• Sign-up bonuses

After reviewing the above features, we based our recommendations on platforms offering the lowest fees, the widest range of investment options, usability and any unique features like access to a human advisor. We also looked into each company's customer support structure and app reviews.

Your investment earnings through a robo-advisor are subject to fluctuations of the market. Your earnings also depends on any associated fees and the contributions you make to your account. There are no guarantees you'll earn a certain rate of return or current investment options will always be available. To determine the best approach for your specific investment goals, speaking with a reputable fiduciary investment advisor is recommended.