An asset class that your author has been researching substantially is cryptocurrency. Bitcoin and the other alt coins, appear to be like very few other investment assets and so far moves in very different ways to almost every other asset. While it is very volatile and high risk and has quite a learning curve, it might be useful for some investors to understand and add to their portfolio.
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.
To make comparisons between companies, sectors and markets a little easier, there are a number of mathematical models used. The most common and often the most helpful is the P/E ratio. The Price to Earnings ratio takes the share price and is divided by the earnings per share. It is possible to calculate this using past earnings, projected future earnings and with all sorts of moving averages ;-) Therefore, this is one number that it is vital for any investor to know and understand.

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Interactive Brokers (IBKR) earns this award due to its wealth of tools for sophisticated investors and its wide pool of assets and markets. The firm makes a point of connecting to as many electronic exchanges as possible. You can trade equities, options, and futures around the world and around the clock. Interactive Brokers’ order execution engine stays on top of changes in market conditions to re-route all or parts of your order to achieve optimal execution, attain price improvement, and maximize any possible rebate. The order routing algorithms seek out a speedy execution and can access hidden institutional order flows (dark pools) to execute large block orders. The wide array of order types include a variety of algorithms as well as conditional orders such as one-cancels-another and one-triggers-another. You can also set up conditional orders based on price, volume, daily P&L, margin cushion, number of shortable shares available, rebate available from the trading venue, and other factors.

The trading products you can purchase using these platforms can include stocks, commodities, derivatives, bonds etc. which can be traded between the traders on the stock market with intermediates such as investment banks, stock exchanges, brokers and market makers. A communication network is set-up between the various intermediates and the traders, which facilitates proper execution of the whole system.