Interesting thread and comments. Thx kiwi for the restatement and focus.
Benson's method,
summarized here without all the medical justifications, is Vipassana 101. Simply sit and practice breath awareness. If this is all one ever does, the potential for further growth, if desired, is there.
The Vipassana one can learn through centers or teachers goes into refinements that shift breath awareness to deeper inner body/mind awareness and in a similar progressive way, to outer world awareness.
While Vipassana arose from the Buddhist tradition, it isn't in itself a spiritual practice requiring one to first believe in a Great Spirit, although every great teacher of Vipassana has, in fact, "believed" in a "Great Spirit". If that idea stands in your way, then stick with Benson's justification for the method and your secular views need not be challenged. For most goal-oriented traders, this is all you're likely to want or need.
If, on the other hand, you do have a ton of practical questions about meditation in more spiritual context, you might enjoy reading
these extracts from Osho, a controversial, now dead, "guru" who certainly had a way with words and of cutting to the heart of things.
Adding Zen or Yoga to the equation is, in my opinion, less a "traders" decision than a spiritual quest decision. Both often involve "systems of belief" that may satisfy curiosity or give a sense of "enlightenment". Seekers seek, I suppose, until they find. For myself, I've found that simply breathing and developing awareness is a very satisfying meal and, as simple as it sounds, not one alway easy to prepare. Life happens and our intentions crumble. But one thing about awareness is that we come to take
full responsibility for our self: we made our self, we can unmake our self, and we can remake our self. Vipassana is the bedrock. Adding other techniques, ideas, or knowledge are like occasional desserts or treats.
best,
amg