hai friend
promoters can participate in trading,they can buy or sell any stock in the market,but in the case of their own co if any body sells or buys their own share in the co if it crosses certain mark they have to inform the exchanges. High promoter holding is good in one way as majority of shares are with them they will have more intrest in the proper running of the company.but the disadvantage is that the promoters can take any decision regarding the co as majority of shares are with them some times investors have to bear big looses due to this.REFER THE CASE OF WHAT HAPPEND WITH ALEMBIC GLASSES
