Is diversification of investment portfolio necessary even at the start?
The concept of diversification is quite broad based. Thus, I would rather leave it to the incumbent set her own rules/canons for defining the parameters of comfort for devising the portfolio. Any courses that can help be a better investor. Basic exposure to concepts of financial accounting and strategy helps to grasp the essentials of stock evaluation. Thereafter, it is learning from experience and the right `teachers’ which matter.