If you choose to be a public servant, i.e., to work for the people, you need to also show integrity and do not appear to personally benefit from any knowledge you might gain. So, either institutes a stock approval system as every bank has in place for its employees or just allow stock index trading, no individual stocks

Even though it is mostly for insignificant amounts, but even the smell of gaining advantage by publicly elected officials should be avoided, so make all lawmakers put their stock holdings either in passive stock investments, hand it over to a trust or institute an approval system as employees at companies have while trading in their own company stock

I feel it should be because the people who control business inherently have insider knowledge, which puts them at an unfair advantage compared to retail or even institutional investors.