In a fast-changing industry, these are seven of the best cryptos to invest in.

October was a blockbuster month in the world of cryptocurrencies, with the asset class's leading player, Bitcoin (BTC), surging by about 40%, according to data from CoinMarketCap. It wasn't just Bitcoin that went parabolic in the month, with several other prominent coins on this list hitting all-time highs. The Shiba Inu (SHIB) coin, which debuted as a spin-off of the meme-based Dogecoin, went absolutely bonkers, gaining more than 800% in the month and leapfrogging Dogecoin (DOGE) in the process. Such unabashedly speculative, meme-based tokens, however, don't stand up to scrutiny. Here's a look at seven of the best cryptocurrencies to buy in late 2021, and the bull case for each.

Bitcoin (BTC)

Bitcoin's recent surge was the result of a few catalysts, not least of which was the launch of the first Bitcoin-focused exchange-traded fund in the U.S. The Proshares Bitcoin Strategy ETF (ticker: BITO) began trading Oct. 19, with excitement over the continued mainstreaming of the digital asset driving BTC to an all-time high of $66,930 just a day later. Bitcoin's invention in 2009 changed money forever and opened the door to blockchain-based, decentralized currencies not issued by any nation. Bitcoin's first-mover status, its hard limit on a maximum circulation of 21 million BTC and its potential to become a store of value on the balance sheets of corporate America -- a future which Tesla Inc. (TSLA) first hinted at with a $1.5 billion Bitcoin purchase announced in February -- make it a must-own cryptocurrency.

Ethereum (ETH)

Next among the best cryptocurrencies to buy is Ethereum, perhaps the only digital asset outside of Bitcoin worthy of being dubbed a blue-chip cryptocurrency. Bitcoin accounts for more than 43% of the entire asset class's market cap, while Ethereum accounts for more than 19%. No other coin has even 4% of the market. ETH has eaten into BTC's market share in 2021, beginning the year with just a 10.8% share. A big reason for Ethereum's growing popularity -- and a key way it's differentiated from BTC -- is its functionality as a platform for decentralized finance, or DeFi. Developers love building decentralized applications, or DApps, on Ethereum, which is actually the most-used blockchain in the world and the go-to network for up-and-coming technology like nonfungible tokens, or NFTs. Ethereum hit all-time highs Oct. 29.

Solana (SOL)

Although 2021 has had its fair share of crypto tokens taking off, Solana might be the year's most impressive underdog story. Beginning the year with just 0.01% of the market, SOL went meteoric and by September had cracked into the top 10 cryptocurrencies by market cap. Excluding stablecoins, SOL has since cracked the top five list. Its Cinderella story has been driven not by silly meme-induced speculative fervor, but its technological ingenuity. Like Ethereum, the Solana protocol was built to facilitate the easy creation of DApps, but the network is actually even faster than Ethereum, has far lower fees and is intended to be more easily scalable than rivals. Solana repeatedly hit all-time highs in late October and early November.

FTX Token (FTT)

The FTX Token is unique among the best cryptocurrencies as the native token for the incredibly successful FTX platform, a crypto derivatives platform, which launched in 2019. The firm has been making plenty of media headlines recently, attracting a $25 billion valuation in a private funding round in October, up $7 billion from just three months earlier. The firm is also gaining mainstream attention from a recent "60 Minutes" profile on the company. As a non-Bitcoin crypto, FTT is a so-called altcoin; the token is up nearly 1,000% thus far in 2021 and has a market cap of more than $7 billion.

Cardano (ADA)

Another token eating away at Bitcoin's dominance is Cardano, which is a top-five crypto if you exclude Tether, which is pegged to the U.S. dollar. Unlike the stock market, there aren't price-earnings ratios and quarterly financial reports to work with when evaluating a given digital currency's value. Qualitative details matter, which is why having Charles Hoskinson, a co-founder of Ethereum, as a Cardano funder gave the coin instant credibility when it debuted in September 2017. With both a hard cap on the maximum number of ADA coins -- the currency on the Cardano blockchain -- and its use of the dramatically more energy efficient proof-of-stake protocol, Cardano combines two attractive coin characteristics.

Binance Coin (BNB)

When they hear the term "cryptocurrency exchange," mainstream investors may initially think of Coinbase Global Inc. (COIN), the first such company to go public in the U.S. But it's actually Binance that's the world's largest crypto exchange, and the native BNB token was initially based on Ethereum but now is issued on its own Binance blockchain. The coin has grown with Binance's popularity, soaring from 10 cents at its initial coin offering in 2017 to about $550 today. BNB is up more than 1,300% so far in 2021.

Yield Guild Games (YGG)

Last and easily least by market capitalization is Yield Guild Games, a far newer and more speculative cryptocurrency than the others on this list. None of the previous picks are outside the top 35 names by market cap, but Yield Guild Games is barely cracking the top 250. With a price history dating only to late July, YGG and its $475 million market cap aren't for the faint of heart, but the ambition of the project makes it an interesting speculative buy. YGG is a decentralized autonomous organization that has built a community of online players and investors who participate in a virtual economy. It invests in NFTs and spreads the revenues from renting out these virtual assets with its "guild members." YGG is up more than 600% from its all-time low, which came shortly after launch, about three months ago.

Seven contenders for the best crypto to buy now:

-- Bitcoin (BTC)

-- Ethereum (ETH)

-- Solana (SOL)

-- FTX Token (FTT)

-- Cardano (ADA)

-- Binance Coin (BNB)

-- Yield Guild Games (YGG)