The 3 major US stock indexes are fresh off record highs. Here's how other popular investments have fared in 2019.

Year-to-date performance: +29% (WTI crude oil)

Sometimes referred to as "liquid gold," oil remains a popular commodity for traders around the world. Recent geopolitical events like the two captured British tankers off the coast of Iran helped drive the cost of oil higher.

Oil prices have outperformed all three major indexes in 2019, with the S&P 500 coming the closest to matching its gains.

Year-to-date performance: +167%

Though far from its 2018 high of nearly $20,000 per coin, Bitcoin experienced a rapid recovery this year. The uptrend began in early April after the price jumped about 20% in a single day, and the surge has only continued.

Bitcoin has healthily outperformed the three major stock indexes so far, but the digital coin's 24/7 trading cycle and high volatility may be too much to stomach for some investors.

Year-to-date performance: -3.6% (Euro versus US dollar); -1.2% (Swiss franc versus US dollar); +2.5% (Mexican peso versus US dollar)

If you sank your dollars into foreign currencies at the start of 2019, odds are your net worth hasn't changed too much. Currencies offered relative stability compared to stocks and other assets, but geopolitical crises or weakening foreign economies can doom a currency-heavy portfolio.

With the US-China trade war going strong and central banks starting to cut interest rates, currencies may take on new volatility through the rest of 2019.

Year-to-date performance: 2.69% annual percentage yield from a Betterment savings account

Though it may seem robo-advisors' high-yield savings accounts don't begin to stack up to the indexes' returns, they have something no other asset on this list has: guaranteed and insured stability.

App-based services like Betterment and Wealthfront offer savings yields far higher than traditional banks' 0.1% interest rate. Betterment recently bested Wealthfront's previous record-high rate of 2.57%.

For investors looking to sink their money in something with minimal volatility and fee-free transfers, these digital banks fit the bill.