Best credit cards for investing your rewards

Bank of America cards are currently not available on CNBC Select and links have been redirected to our credit card marketplace where you can review offers from other issuers like American Express or Chase. You can also check out our list of best credit cards for alternative options.

The TD Ameritrade Client Rewards Card is not currently available to new cardholders.

Investing consistently in the stock market regardless of its current conditions — a strategy called dollar cost averaging — may help grow your money over a long period of time.

"The reason I like this technique is because it helps simplify, streamline and automate your finances," Sophia Bera, CFP® from Gen Y Planning tells Select. Cash-back cards can deliver over $1,000 in rewards each year, depending on your spending habits, and these earnings could appreciate depending on the stock market's performance. Meanwhile, other redemption methods such as Pay with Points might actually devalue your rewards.

But before you look to the stock market, tend to your essential financial priorities first, advises Bera.

"I would first make sure that you have adequate emergency savings, have eliminated credit card debt and are on track for retirement before I would recommend that you use cash-back rewards for a brokerage account," she says.

If you've checked off all these boxes and feel ready to automate your cash-back investing, it may be time you add a new credit card to your wallet. To get you started, we analyzed the most popular cash-back investing credit cards to help you make the most of your points, and we round up our top 6 picks for you below.

• Best for Merrill Lynch: Bank of America® Premium Rewards®
• Best for Fidelity: Fidelity® Rewards Visa Signature® Card
• Best for Charles Schwab: American Express Platinum Card® for Schwab
• Best for Morgan Stanley: The Platinum Card^® from American Express Exclusively for Morgan Stanley
• Best for TD Ameritrade: TD Ameritrade Client Rewards Card
• Best for College Savings: Upromise® Mastercard®

Who's this for? If you're an eligible Merrill account holder who wants an easy, hands-off way to pad your investments, the Bank of America® Premium Rewards® card could be a good choice.

You can also redeem rewards for a statement credit, gift cards or purchases at the Bank of America Travel Center.

You'll earn 2 points per $1 spent on travel and dining purchases and 1.5 points per $1 spent on all other eligible purchases, which puts this card on-par with some of our best cash-back rewards cards.

And if you have a large purchase coming up, you can earn 50,000 bonus points once you spend at least $3,000 in purchases in the first 90 days from the account opening.

Additionally, the Bank of America Premium Rewards card comes with emergency travel benefits like trip cancellation/interruption insurance, trip delay reimbursement, lost luggage and baggage delay insurance and transportation assistance for both emergency and non-emergency situations

There is a $95 annual fee, but it is easily offset if you take advantage of the annual airline incidentals credit of up to $100. There's also a Global Entry/TSA PreCheck credit of up to $100 every four years, and no foreign transaction fees.

Who's this for? The Fidelity Rewards Visa Signature Card is ideal for anyone with a qualifying Fidelity brokerage or investment account.

You can earn 2% cash back on all eligible spending and put your earnings to work through Fidelity. This card boasts the highest flat-rate cash-back rate among investment credit cards. At this rate, every $2,500 you spend with your Fidelity Rewards card equals a $50 deposit into your eligible Fidelity investment account(s). You can deposit your rewards in up to five accounts at a time. Qualifying accounts include:

• Fidelity^® Brokerage account
• Fidelity^® Cash Management account
• Fidelity^®-managed 529 college savings plan
• Retirement account
• Fidelity Go^® account
• Fidelity Charitable^® Giving Account^®
• Fidelity HSA^®

Like other Visa Signature^® cards, the Fidelity Rewards card comes with an array of perks for both safety and leisure, including 24-hour concierge service; special offers on travel, dining, sporting, entertainment and shopping; emergency cash and card replacement; travel and emergency assistance services; accident services and auto rental collision damage waiver; lost luggage reimbursement; and roadside dispatch.

Who's this for? The American Express Platinum Card® for Schwab is for Amex loyalists with qualifying Charles Schwab investment accounts who want to benefit from the same premium perks the Platinum card is known for while investing their Membership Rewards® points for even greater earnings. 

Known for its premier travel benefits, the Amex Platinum Card delivers 5X Membership Rewards® points on flights booked directly with airlines or with American Express Travel and on prepaid hotels booked on amextravel.com; 1X points on all other eligible spending.

New cardmembers can earn 100,000 Membership Rewards^® points after you spend $6,000 on purchases on your new card in your first 6 months of card membership

In addition to the Amex welcome bonus, Charles Schwab account holders can receive additional cash boosts when their holdings reach the a certain thresholds at the time of account approval (and annually thereafter):

• $100 card statement credit if your qualifying Schwab holdings are equal to or greater than $250,000
• $200 card statement credit if your qualifying Schwab holdings are equal to or greater than $1,000,000

Like with the traditional Amex Platinum Card, there are no foreign transaction fees with the Schwab card. While the $695 annual fee is steep, it can be offset if you take full advantage of the Global Lounge access, the $200 annual airline credit, Global Entry or TSA PreCheck® fee credit (every four years) and monthly Uber Cash payments of $15 (and $20 in December). These perks, in addition to the possible investment yields, can easily outweigh the annual fee.

There is a no annual fee alternative: The Schwab Investor Card^® from American Express lets qualifying Schwab account holders earn an unlimited 1.5% cash back to roll into their investment accounts. Plus, there's an introductory 0% APR on purchases and balance transfers for six months (then 13.99% to 16.99% variable APR).

Who's this for? The Platinum Card® from American Express Exclusively for Morgan Stanley also comes with high-end travel benefits and access to luxury hotels and airport lounges worldwide. If Platinum perks appeal to you and you have a qualifying Morgan Stanley account, this card can help you grow your portfolio while you travel.

Cardmembers earn 5X Membership Rewards® points on flights booked directly with airlines or with American Express Travel; 5X Membership Rewards® points on eligible hotels booked on amextravel.com; and 1X points on all other eligible spending. With Invest with Rewards, you can deposit Membership Rewards points to your qualifying Morgan Stanley brokerage account. 

There is also a welcome bonus of 60,000 Membership Rewards® points after spending $5,000 in purchases in the first three months of card membership. This is equal to a $600 deposit into your Morgan Stanley account.

There are no foreign transaction fees with the Morgan Stanley card, but there is a considerable annual fee of $550. However, you can offset this cost if you take full advantage of the annual $200 airline fee credit, Global Entry or TSA PreCheck® fee credit (every four years), access to the Global Lounge Collection and up to $200 in Uber savings.

Those with a qualifying Morgan Stanley Platinum CashPlus brokerage account will also be eligible to earn an annual Engagement Bonus of $550 and get a free supplemental card. There is no minimum spending requirement to receive this perk.

If you're looking for a no annual fee alternative, consider the Morgan Stanley Credit Card From American Express. It comes with a welcome bonus of 10,000 Membership Rewards® points after you spend $1,000 in purchases in the first three months. Earn 2X Membership Rewards® points on airfare purchased directly from airlines, purchases at U.S. restaurants and select U.S. department stores and car rentals booked directly with select car rental companies. Earn 1X points for all other eligible purchases (terms and limitations apply). You can use your Membership Rewards® points to deposit cash into your qualifying Morgan Stanley brokerage account.

Who's this for? Similar to the Fidelity Rewards Signature Visa, the TD Ameritrade Client Rewards Card is a flat-rate cash-back card. It offers 1.5% cash back on all purchases, with no caps or limits. When you invest your cash back into an eligible TD Ameritrade account, you receive a 10% bonus.

According to the online cash-back calculator, the average cardholder can earn about $726 in cash back each year. There are a variety of other redemption methods, including travel, shopping and gift cards. But the most valuable redemption method by far is investing. 

This card has no annual fee and foreign transaction fees. 

Who's this for? If saving for your children's college tuition is at the top of your priority list, the Upromise® Mastercard® lets you invest in a 529 plan so that you're ready when that important day comes.

Whether you invest your rewards or not, the Upromise Mastercard offers 1.25% cash back on every qualifying purchase, but when you link your card to an eligible 529 College Savings Plan, you'll earn 15% more on the money you deposit.

The Upromise Round Up option lets you round up your purchases to either the nearest dollar, or even up to the nearest $500. The difference between the purchase amount and the round up amount will count as a purchase and will also earn cash back.

Cardholders can also take advantage of free two-day shipping and free return shipping on eligible purchases thanks to a complimentary ShopRunner membership.

With no annual fee or foreign transaction fees, this card helps parents put saving for college on autopilot. Additionally, there is a $100 welcome bonus when you spend $500 or more in your first 90 days. 

To determine which cards will put the most money back in your pocket, Select evaluated 50 cash-back credit cards offered by the biggest banks, financial companies and credit unions that allow anyone to join. We compared each card on a range of features, including cash-back rewards, annual fee, welcome bonus, introductory and standard APR, balance transfer fee and foreign transaction fees, as well as factors such as required credit and customer reviews when available.

While investing your cash-back rewards is an easy way to passively invest in the stock market, it is not a comprehensive financial plan. Investing cash back rewards is an added benefit to card membership and not meant to not replace retirement savings or emergency savings.

Information about the Morgan Stanley Credit Card From American Express and Schwab Investor Card® from American Express has been collected independently by Select and has not been reviewed or provided by the issuer of the card prior to publication.