Lot
What it is:
How it works (Example):
Lots are the standard trading amount, and thus they usually incur the most favorable commission costs. For example, if you wanted to buy six lots of Company XYZ stock, you would be buying 600 shares.
Investors, especially individuals, frequently cannot or do not want to bear the expense of trading shares in round lots, however, which is why most brokers also accept “odd-lot” trades (though they may charge a higher commission for doing so). However, the advent of electronic and online trading platforms has reduced, and in some cases eliminated, these odd-lot premiums.
Why it Matters:
Lot investors tend to be larger investors. The ratio of odd-lot buying to odd-lot selling, on the other hand, is often used to evaluate small-investor sentiment.
Source: http://www.investinganswers.com/financial-dictionary/stock-market/lot-5075
What is a ‘Standard Lot’
A standard lot is the equivalent to 100,000 units of the base currency in a forex trade. A standard lot is similar to trade size. It is one of the three commonly known lot sizes; the other two are mini-lot and micro-lot.
BREAKING DOWN ‘Standard Lot’
A standard lot represents 100,000 units of any currency, whereas a mini-lot represents 10,000 and a micro-lot represents 1,000 units of any currency. A one-pip movement for a standard lot corresponds with a $10 change. For example, if you buy $100,000 against the Japanese yen at a rate of ¥110.00 and the exchange rate moves to ¥110.50, which is a 50 pip movement, you have made $500. Conversely, if the exchange rate falls 50 pips to ¥109.50 your net profit and loss is minus $500.
With the advent of online brokers and increased competition it is possible for retail investors to make trades in amounts that aren’t a standard lot, mini-lot, or micro-lot.
In the interbank market where banks trades with each other on platforms such as Reuters and EBS, the standard trading size, or standard lot, is 1 million units in the base currency.
Source: https://www.investopedia.com/terms/s/standard-lot.asp
Odd Lot
Even Lot
A normal unit of trading for securities or bonds. An even lot purchase of stock is 100 shares, while an even lot purchase for bonds is five shares. A stock transaction that involves less than 100 shares is considered an odd lot and may incur higher trading fees on a fee-per-share basis.
BREAKING DOWN ‘Even Lot’
Investors may realize cost savings the more shares that they purchase. Institutional investors, for example, trade in much larger lots and can spread costs over more shares. Trading in large even lots results in enhanced market liquidity and minimizes the impact of trading spreads.
Also referred to as round lots or full lots.