For the past 13.5 months, investors have enjoyed one of the most epic rallies in history. After fear gripped the stock market for a five-week period during the first quarter of 2020, equities have torched higher. The iconic Dow Jones Industrial Average, broad-based S&P 500, and technology-focused Nasdaq Composite have returned 84%, 86%, and 99%, respectively, since hitting their bear-market bottoms on March 23, 2020.

Considering that the stock market has delivered a historic annual average return of 7%, including dividend reinvestment, these are stellar gains. But for a trio of investments, a gain of even 98% would represent mere peanuts.

If people had the wherewithal, stomach, and luck to put $35,000 into any of these three assets just six months ago, they'd be millionaires today.

A messy stack of one hundred dollar bills.

Image source: Getty Images.

Ocugen: A $35,000 investment is now worth $1.56 million

With the only parameter being a market cap of at least $300 million, the top-performing stock over the trailing six-month period, and the one that would have turned $35,000 into well over $1.5 million, is clinical-stage biotech stock Ocugen (OCGN -20.28%).

Though Ocugen's name rightly implies that it seeks to develop treatments to cure blindness diseases, it's the company's coronavirus disease 2019 (COVID-19) vaccine candidate, Covaxin, that's turning heads. Covaxin is being developed in partnership with India's Bharat Biotech.

On April 21, Bharat released its second interim analysis of Covaxin, which is being examined in a late-stage study of 25,800 participants in India. Though the vaccine showed 78% effectiveness after the second dose, it was the 100% efficacy against severe disease, including hospitalization, that got the medical community and investors excited. Providing 100% protection from severe disease in a country currently ravaged by COVID-19 offers game-changing potential. 

Furthermore, on May 3, Ocugen announced that Covaxin was potentially effective against three known variants of COVID-19: the U.K. variant, India's double mutation, and a lesser-common Brazil variant. This builds on the second interim analysis efficacy data released two weeks earlier. 

What remains to be seen for Ocugen is if Covaxin has a path forward in the United States. Not only is the U.S. the leading moneymaker for drug companies, but it's the only country for which Ocugen has licensed Covaxin from Bharat. If approved in the U.S., the duo would share commercialization profits. It's not clear if the U.S. Food and Drug Administration will accept trial data from India as enough for emergency-use authorization (EUA) in the United States. It's also concerning that the 2021 inoculation campaign will likely be over if and when Covaxin is given that EUA. 

Suffice it to say, Ocugen is a total dart throw at its current valuation.

A person holding a glowing golden lock that's surrounded by a latticework representing blockchain.

Image source: Getty Images.

Takung Art: A $35,000 investment is now worth $1.04 million

Hong Kong-based Takung Art (TKAT), which didn't even have a $10 million market cap as recently as the end of September, now sports a $344 million market cap and is the hands-down top-performing stock on a year-to-date basis (up 1,968%). Back out to the trailing six-month period, and Takung would have turned a $35,000 investment into $1.04 million. For you math-phobes, that's a return of 2,871%.

How are such enormous gains possible? One of the biggest catalysts for Takung is the emergence of non-fungible tokens, or NFTs. Without getting overly complicated, an NFT is like a digital certificate of authenticity stored on blockchain. This means it can't be altered or stolen, which would prove an NFT buyer to be the rightful owner of a digital piece of art. In recent weeks, we've seen some NFTs sell for millions of dollars.

What does that have to do with Takung Art, you ask? Takung runs an online platform that allows artists and art dealers to sell or trade in artwork. Keep in mind that artwork is a broad term and can include paintings, sculptures, and even jewelry. The company's surging share price appears to be the result of investors betting on Takung Art jumping into the NFT space. It already has the online platform to make the transition relatively seamless.

Additionally, the company has a very small float of just 9 million shares. It's not uncommon for small-cap and micro-cap stocks with small floats to be driven by investors' emotions from time to time.

The concern here is that Takung Art has given no indication that it'll jump into the NFT space. What's more, its sales have deteriorated over the past couple of years. In 2020, the company didn't even generate $4.6 million in revenue. By comparison, Takung brought in $4.9 million in sales alone in the fourth quarter of 2016. This looks to be a stock best left on the auction block. 

Two diverging charts leading to a digital rocket that's ready for launch.

Image source: Getty Images.

Dogecoin: A $35,000 investment is now worth $9.34 million

But when it comes to runaway returns over the trailing six months, cryptocurrency Dogecoin (DOGE 1.49%) takes the cake. After beginning the year at $0.0025 (that's a quarter of a penny), Dogecoin was going for almost $0.67 per coin as of very early morning, May 5. That's a return of more than 26,500% in just six months, and it would have turned a $35,000 investment into $9.34 million. No, that's not a typo.

Although seemingly all cryptocurrencies have been hot, Dogecoin has caught fire as the perceived coin of the common folk. Enthusiasts regularly point to its lower transaction costs, relative to Bitcoin and Ethereum, as a core reason for its success, as well as growing adoption by businesses. Buyers also believe its low token price represents opportunity -- i.e., it's a lot easier, in theory, to double an asset at $0.67 than, say, Bitcoin at $54,000. And then there's Tesla CEO Elon Musk, who has regularly tweeted support for Dogecoin.

What's baffling about this move, in particular, is that Dogecoin has nothing tangible in its sails. While it has lower transaction fees than Bitcoin and Ethereum, there is no shortage of cryptocurrencies with lower transaction fees and faster validation/settlement than Dogecoin. That's one of the downsides of the crypto space having virtually no barrier to entry.

Dogecoin's utility is almost nonexistent, too. In eight years, we've seen this literal joke of a token attract 1,300 businesses that'll accept it as payment. There are more than 32 million businesses in the U.S. alone and an estimated 582 million entrepreneurs worldwide. Dogecoin has little use beyond the exchanges it's traded on.

But the real head-scratcher is that Elon Musk has become this coin's biggest catalyst. Payments, transaction validation, and utility have all taken a back seat to hoping Elon Musk sends out a tweet every day with the word Dogecoin in it. This alone makes Dogecoin a strong candidate to completely bust in the very near future.