I don't think that you should invest based on the Democratic or Republican conventions being televised. The truth of the matter is that the affect of a President's party or the convention to select him is too infrequent to have any statistical significance. There is no way that a Confident Investor could surmise that a specific stock will rise or fall based solely on the political party of the President of the United States of America.
Even though I don't think it is a wise investment strategy, it is interesting to engage in trivia discussions over wine, coffee, or the water cooler with fellow investors. So in that spirit, I reference a recent article on MarketWatch. I am only putting two of the paragraphs here but it is probably worth your effort to click over and read the entire article.
In the 16 presidential election years since 1948, the S&P 500-stock index has risen during 11 Republican conventions, as measured from the start to the end of the convention, according to a report by S&P Capital IQ. In contrast, stocks notched gains during only seven Democratic conventions.
When markets reacted favorably during one convention, they tended to drop during the opposing party’s convention. That suggests that if markets rise this week while Republicans are meeting, the odds are, stocks might drop when Democrats hold their convention in Charlotte, N.C., Sept. 3 to 6, says Sam Stovall, chief equity strategist for S&P Capital IQ.