An odd lotter is an investor who purchases shares or other securities in small or unusual quantities.
Odd lot theory was predicated on the belief that one could outperform the stock market by identifying the least-informed investors and making investments opposite to them.
(If the least-informed investors were selling, it was generally a good time to buy, and vice versa.
According to Princeton University economist Burton Malkiel: "It turns out that the odd-lotter isn't such a stupendous dodo after all.
[7] The term odd lot existed prior to use in finance and is used outside the financial industry for any irregular packaging in a general and objective sense.