Block trades are large trades with at least 10,000 shares of stock. Because of their large size, block trades can normally only be initiated by institutionals.
Block trades volume help trades measure the activity of institutional investors for a particular stock or security.
Depending on the liquidity of a particular stock, block trades or block orders can affect the market price of that stock; unless these block trades occur directly between two institutions. In that case, the institutions can agree on a fixed price and the transaction will occur at that price.
In bonds trading, a trade is usually considered a block trade when the transaction exceeds $200,000.
Trading financial instruments, including foreign exchange on margin, carries a high level of risk and is not suitable for all investors. The high degree of leverage can work against you as well as for you. Before deciding to invest in financial instruments or foreign exchange you should carefully consider your investment objectives, level of experience, and risk appetite. The possibility exists that you could sustain a loss of some or all of your initial investment and therefore you should not invest money that you cannot afford to lose. You should be aware of all the risks associated with trading and seek advice from an independent financial advisor if you have any doubts.