What's the difference's and similarities between Today's Stock Market and the Stock Market of 1920?
I agree with the previous set of thoughts in that there is little in common with the practices of the stock market between both time periods. The most obvious similarity is that the stock market of today and of 1920 are seen as essential to generating wealth. Yet, outside of that, there is little in way of similarity. One particular reason why this is might be due to the economic climate of both time periods. There was a period of expansion and growth in the 1920s, whereas right now is a period of contraction. The practices of purchasing stock and generating money from 1920 to now are vastly different. There are more guidelines and regulations that govern stock practices today than there were in the 1920s. There is probably a great deal more transparency now than there was in the 1920s, as well. This is probably because the market of the 1920s is seen as a benchmark that needs to be avoided in terms of practices and habits that actually did more to hurt the economy than anything else.
I do not think that there is a great deal of similarity between the stock market now (especially after the financial crash of late 2008) and the market in the time leading up to the Great Depression.
In those years, the Dow Jones Industrial Average was shooting up very rapidly. This was driven by speculation and by margin buying. Right now, the market is climbing gradually and is still nowhere near to the record highs it experienced about 5 years ago. In addition, there is little of the margin buying that went on in those times.
If you had asked this question 3 or 4 years ago you would have had a better case to make.