Today marks the start of the last quarter of the year
Are you sure about this? Generally, a quarter should start with October and end with December. Depending on countries, this combo might be 4th or 1st quarter (fiscal year). But I don't know if there's somewhere a quarter starts with September.
Do not be of the opinion that a coin has already increase in price therefore it can not increase further when they are quality projects, such mindset should not make you go searching for new gem and end up buying into Scam coins instead explore more possibilities in those well known project. Project like Solana, DOT, BNB, BTC, ETH can still give you good profit and you investing now does not mean you would be profiting less.
Of this I agree, good projects always result in profit, more or less. It's better to put a large amount of budget on well known coins and spend a little on lesser known or new projects as a way of gambling.