If you prefer to keep all of your eggs in ONE BASKET, you REALLY need to WATCH THAT BASKET.
I prefer to diversify and trade multiple positions as different stocks have different Watch/Buy/Hold/Sell cycles and I can trade the gain cycle while waiting on other stocks to gain.
And benefit of multiple position trading is instead of potentially making few hundred percent on your single position trade return or losing (say in 6 months), you can potentially make several thousand percent as you only trade on gaining stocks.
To me, it's all about total percentage return on my trades.
Think about it.
And if you are concerned about losing your gains due to commission cost of performing multiple trades, consider Firstrade brokerage with $0, yes "No commission" cost - https://www.firstrade.com/content/en-us/pricing
Firstrade restricts OTC stocks below certain price but if you are REALLY SERIOUS about "stock trading" (Yes, that's what you are doing and not "investing"), you should be focused on high volume stocks not just on OTC (Due to sub penny price, many OTC stocks are artificially "high volume") but on listed stocks of the big boards (NYSE, Nasdaq, AMEX).