What is an Altcoin? Altcoin 101 for Beginners - Intro to Altcoins
Altcoin stands for "Alternative Coin"
In the early days of Digital Assets and Cryptocurrency, the primary coin starting in 2009 was only Bitcoin (BTC). As other coins came onto the scene, everything else was referred to as an Altcoin (Alternate coin to...). The Crypto market was dominated (dominance) by Bitcoin and all the other Altcoins followed in the direction of Bitcoin (Crypto cycles and Bitcoin Cycles). In 2021 it has Ethereum has been considered the breakaway from Altcoins (depending on who you ask).
The general connotation is that alt coins are more risky than Bitcoin and Ethereum. They are newer or don't have the same history and fundamentals as Bitcoin and Ethereum.
As time goes on in the Crypto world, more and more coins will start to become "blue chip" and move away from being classified as an alt coin.
How many Altcoins exist today?
There are currently over 13,000 coins in exisitance. Many of these hold little to no value.
The majority of the current Total Crypto Market Cap is held by the top 10 coins. Roughly 80% of the TMC is in the top 10 coins.