You can buy more shares if you are sure they will return you big fortune. There is no one fit for all rule. Every share offer different opportunities. Do a proper research on each one and then treat each one accordingly.
Master basic chart-reading skills and you will be able to more consistently identify the best prices for entering and exiting your trades. Your bottom line can improve dramatically as a result.
German Finance Minister Schaeuble has already warned Greece against straying from a path of economic reform, saying any new government would be held to the pledges made by the current Samaras government.