Diversification allows you to recover from the loss of your total investment (20% of your portfolio) by gains of 10% in the two best companies (25% x 40%) and 4% in the remaining two companies (10% x 40%). Even though your overall portfolio value dropped by 6% (20% loss minus 14% gain), it is considerably better than having been invested solely in company E.
A word on exchange balances: it is NOT RECOMMENDED to keep your cryptocurrency assets on exchanges. There are countless documented cases of people who lost access to their funds, either because their account was disabled, or because legislation forbade the exchange operator to give access to users based on their geographical location. Some exchanges have been hacked in the past and will be hacked. It is RECOMMENDED that you use your own wallets, that you secure them properly (more below) and that you limit the cryptocurrency held in exchanges only to carry the business/transactions you have to, and for the most limited amount of time, to reduce exposure.
For the active trader, execution speed and fill price are very important. I won’t get too in depth here but I have tested many of these brokers and there can be noticeable differences in trade execution times and quality. For the majority of investors, saving a penny per share on a 100 shares order isn’t the end of the world, but for active traders it is something to look into. To understand Order Execution, read this guide.
Finally, one point to mention is that a given cryptocurrency can be listed in more exchanges, with different listing prices (see below – Arbitraging). The best place to look for a cryptocurrency listing in term of total market capitalisation is Coinmarketcap. Cryptocurrencies are listed per descending order of market capitalisation; the site also allows to deep-dive on each cryptocurrency to see their value over time and where they are listed. Some cryptocurrencies may be listed on several exchanges but only 1 or 2 exchanges may see the critical mass of transactions taking place.
Security and Validity of Transactions: While more participants are important for efficient working of a market, the same market needs to ensure that all participants are verified and remain compliant with the necessary rules and regulations, leaving no room for default by any of the parties. Additionally, it should ensure that all associated entities operating in the market must also adhere to the rules, and work within the legal framework given by the regulator.
Secondly, this is a very vast topic and many people now trade and deal with cryptocurrency as their main day job. Startups and empires are built on it, so please understand this is a beginner’s guide and not the ultimate guide to the galaxy of cryptocurrencies. I will specifically limit myself to cryptocurrencies and will not cover ICOs (Initial Coin Offerings) as these are to me more investments into products or companies yet to be developed. This article will also not cover the relevancy or not of cryptocurrencies, it will not cover the famous Tulip Bubble, or any kind of philosophical concepts.
Dollar-cost average: This sounds complicated, but it’s not. Dollar-cost averaging means investing a set amount of money at regular intervals, such as once per week or month. That set amount buys more shares when the stock price goes down and fewer shares when it rises, but overall, it evens out the average price you pay. Some online brokerage firms let investors set up an automated investing schedule.