Dogecoin has its niche, and could be adopted by millions of users, so it is normal that it is among the largest cryptocurrencies and that's why it's been included in this Robinhood list
One whole heck of a lot of cryptocurrencies are now on Robinhood, including the following. Bitcoin, Ethereum, Ripple, Bitcoin Cash, Litecoin, Qtum, Ethereum Classic, Stellar, NEO, Zcash, Monero, Dash, Bitcoin Gold, Lisk, OmiseGO, and Dogecoin. As they say on Sesame Street: Which one doesnt belong? Its baffling to see Dogecoin amongst these other major coins but who knows?https://www.slashgear.com/stock-app-robinhood-ads-no-fee-bitcoin-trading-25517052/Many underestimate the potential of Dogecoin project. There"s a bright future fore DOGE! Just remember that Vitalik Buterin once tweeted that Doge is his huge crush and he will hodl it for a very long time.
What potential can there be for dogecoin, are you serious? Explain to me then the meaning of this project and what is the use of it for society? What important problem does this project solve? A coin is a joke and no more, why such a large capitalization is a mystery to me. It's not serious to talk about prospects at all!

Dogecoin is the perfect currency for the normal user, young people, and the community that uses the Internet as a diversion, away from speculative projects or dark intentions that currently surround cryptocurrencies, the fact that it was created as a joke and not as a pyramid scheme is an advantage.
Many people want this to be the currency of fun, friendship, and altruism, a currency used to thank for content, make donations, micropayments, tips, use it in video games, competitions, gambling, etc.
It has the backing of a growing community, it's fast, it's cheap, it's easy, with almost free transactions, without confusing decimal figures, and it has its own pet which is very important for its brand and promotion, everyone knows the Twitter bird, Firefox fox, Playboy rabbit, Linux penguin, Ferrari horse, Redbull bull, and now Dogecoin dog.
Many people decide to start with Dogecoin for some reason, why can not it be a success?
And don't forget that is has 10x the transactional capacity of bitcoin - out of the box without needing anything like segwit =)