Hallo Kast,
1. Starting with $ 10000 I would advise a Mutual Fund that has good reputation and a relatively high volatility. This way you avoid the risk of a single equity diving deep. For beginners that is an unnerving experience and even with two equities this can happen on both at the same time. You should select two equities that have a general "inverse” relationship(negative correlation) so that as one dives the other goes up and you can liquidate some of the profits to buy the dropping equity. This keeps the Reserve in stand longer. The First Rule is however is: Never invest more money that you are not prepared to lose..
The trading cost on mutual funds are much lower than for single equities, so the minimum trades can be much smaller. . . .trading more often gives you experience( you have you nose on the market more frequently).
Also, invest only in business that you have an affinity with. . .something you would “get into” if you had a million $ to spend! Investing should be fun. This makes the investment "fit" your personality and it will make you more tuned into the market because of it. Read plenty of articles on investing and market signals! Also be prepared to Bail Out in time if you do not have the confidence that a diving equity will recover. For this you need to study the fundamentals.
2. With $ 20000, that I could afford to lose, I would set up an AIM Mutual Fund Portfolio with say 4 different mutual funds of your liking in it. Then "AIM" the individual equities to reap the volatility profits, just like you would with "inverse" equities.. . .again choose equities with negative correlations if you can find them.
I advise you to select yourself which equity to start with. It will "force" you to investigate it's fundamentals, at least the most obvious ones that are important for AIMing such as high volatility and a prospect to last a long time. . .if you let others decide then you are not "on your toes" and not "on the ball". If you make your own selctions and do well you can praise yourself. . .if you lose then you can not blame others.
Keep reading!
