Trading style and age are related to some extent. It is not a matter whether one can design and automate intraday medium frequency system but whether the constant research and updating that is required when involved with this trading timeframe can be performed unless one employs people that do that. But as far as individual traders there is a definite link between age and trading style.
|Intraday||< 40||New York|
|Medium-term positions||< 65||San Diego|
* Typical location that is compatible with the trading style
A 30-year old trader could also be a longer-term trader but being an intraday trader or a scalper is a very demanding task, physically and intellectually, that is more appropriate for younger people.
Longer-term trading includes trend-following and is more appropriate for people who have retired and wish to travel around the world and have time for recreational activities.
None of the above trading styles is easy. All trading methods and timeframes have difficulties and their pitfalls and can result in total loss of capital. But timeframe is important and should be chosen so that that it is compatible with lifestyle.