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Personally am caught between the two. OG means Old Generation. There are OG tokens and there are gems. There are tokens in the market which has been existing for 5,6 years or more. They're referred to as OG and the ones just coming to the market are referred to as Gems. Traders are caught between trading OG or Gem. Some people have the knowledge to look for the two and make good profit from them. The fact the Ethereum is number 2on the market chart does not make it the second oldest or oldest. There are token far older than that like Link, Ada even Doge have been in the market for more than 4years.
OG coin have their own circle. If you find a coin and OG coin that is not less than 5years and also among the top 100 cap, that's going to be a good coin to invest in. You need to be patient with OG coin, they don't move in a flash or weekly. You will need to hold them for between 6 to 7 month for significant price action and it will be worth while. They don't disappoint and you don't suffer the stress of checking your account or wallet daily or hourly. If you invest good amount of money, you'll be sure of a good returns.
Some people bought into Bitcoin for a long time before now, some others bought into it at the beginning of 2020 and they're are better for it now.