TD Ameritrade offers a full portfolio of investment products, which include not only traditional stocks and bonds, but also futures, Forex, foreign ADRs, and even IPOs for some accounts. Fees are near average for the industry, while there’s commission-free trading for some investments, but you still face high rates for broker-assisted trades. Ameritrade does not assess fees on inactive accounts or partial transfers, but there is a $75 charge for every full transfer you make.
Another important thing to consider is the distinction between investing and trading. When people talk about investing they generally mean the purchasing of assets to be held for a long period of time. These types of investments are usually made to reach a retirement goal or to put your money into assets that may grow faster than it would in a standard savings account accruing interest. Trading, on the other hand, most commonly involves the buying and selling of assets in short periods. Trading is generally considered riskier than investing.

As you near retirement, a full-service brokerage firm may make more sense because they can handle the complex "stuff" like managing your wealth in a tax-efficient way, or setting up a trust to pass wealth on to the next generation, and so on. At this point, it may be advantageous to pay 0.50%-1% of your assets in fees each year for advice and access to a certified public accountant who can help you with the nitty-gritty details that are more important as you start making withdrawals (rather than contributions) from your retirement accounts.
His book is a big beast at more than 600 pages and will need to be committed to, but it offers some fantastic insights into how to invest safely and profitably for the long-term and how to make your money work harder. Having interviewed all these legendary traders and investors, the book contains some excellent insights into asset allocation and portfolio planning that almost everyone should gain some benefit from reading.
Astute readers will realise that the above guidance is mainly taking different angles to help prepare for and guide decision making by the investor. The ability to confidently make decisions is vital for investment profits and long-term success. This pdf about the decision making models of Charlie Munger (business partner to Warren Buffett at Berkshire Hathaway - both are certified investment immortals) is almost certain to prove helpful.
In the professional world, one of the key concepts is diversification. Harry Markowitz is a Nobel prize winning economist and one of his major discoveries was that adding new asset classes can dramatically alter the overall risk profile of a portfolio. His finding was that a portfolio that contained very low risk assets would normally benefit from lower volatility and higher returns if a higher risk asset was added. This is due to the likely lack of correlation between high and low risk asset classes.
E (Very Weak) - The stock has significantly underperformed most other funds given the level of risk in its underlying investments, resulting in a very weak risk-adjusted performance. Thus, its investment strategy and/or management has done just the opposite of what was needed to maximize returns in the recent economic environment. While the risk-adjusted performance of any stock is subject to change, we believe this fund has proven to be a very bad investment in the recent past. 

Understand the risks associated with the stocks you are investing in. In the company’s 10-K, there is an extensive section that talks about the company’s risks. You also need to understand your own tolerance for risk. If you invest in a stock that is highly volatile and you are not comfortable with market fluctuation, owning the investment will make you anxious and more likely to sell when it does not make sense strategically.
If you’re an active trader looking to try your hand at beating the market, you probably have a good idea of what you want in a brokerage: low costs, premium research, innovative strategy tools and a comprehensive trading platform. Below, we’ve selected the best online brokers in a variety of categories so you can choose one based on your personal priorities.