one market or more


New trader here...wondering if someone can make a living daytrading just one market or do you need to learn how to handle multiple markets
to have longevity trading?
thanks
1 ... after you are a winner 80% of the days, 2 ...
I started with many stocks, same set-ups. Then went only to ES for a very long time. Now I trade ZB, 6e, NQ, EMD, GC, and ES. Most of the time never more than 2 at a time.
In a book I read called Sniper Trading by George Angell he says that that the pros trade just one market and more importantly trade in just one way (swing, scalper etc). In this way they are very familiar on how their market acts, where the highs and lows are and other key points etc.
I would think that when a market enters a very choppy period as ES is now and if their style is not working well at this time they could move to a second market or simply take a break from trading.

I have my hands full just following ES because I collect a lot of data, and I am new at day trading (about 1 year) so I couldn't trade more than it right now. But if your system is a simple one that works in more than one then I guess move to a market better suited to your system.

All the best
starting out - pick one market. There are plenty of setups in most of the financial futures and once you figure out your edge - add volume to get the desired profit.