I want to understand the rationale to make the decisions to invest in small vs mid cap stocks. If there are any pointers for a non-finance expert, I will really appreciate it.
Small companies are generally able to adapt quickly to take advantage of changing conditions to enter new markets when the economy is growing. This gives them a lot of growth potential under those circumstances. However, in times of crisis, there may not be a lot of new markets to enter, and financing to expand any operations may be impossible to get. Under these conditions, small-caps will suffer relative to large-caps.
In general, small cap stocks are exposed to more downside during recessions and when credit is tight, because it is more difficult for small companies to raise capital, and minor variations in cash flow have a bigger impact.
Coming out of recessions or when credit is cheap, small companies generally perform better than larger companies.
In the depths of recession, small companies with good cash flow are often great value investments, as analysts and institutional investors "punish" the entire class of smallcap companies.