The Apple stock split and even lot trading

Who Cares What Apple's Stock Price Is?
Excerpt:

... if the split doesn't have any economic impact, why bother? I've seen two explanations. One is that doing this will probably get Apple included in the Dow Jones Industrial Average.

Who cares about round lots? Historically, "trading commissions for odd lots are generally higher on a percentage basis than those for standard lots," and I suppose someone somewhere is still being charged extra to trade odd lots. But in the real world, it costs $9.99 to trade one or six or 100 or 10,000 shares of any stock; that is the price to trade stock, it has nothing to do with lots.4 Your cost to buy 100 shares of New Apple for $8,000 is the same as your cost to buy 14 shares of Old Apple for $8,000: $8,009.99. But round lots do matter, for market structure reasons. Odd lots -- orders of fewer than 100 shares -- are treated differently under the Securities and Exchange Commission's national market rules. They are not part of the national best bid or offer, and are not "protected orders" under Regulation NMS ...

The higher the dollar price of a stock, the more odd-lot trades there will be, and the wider the spread will be.8 So high dollar prices pretty directly take money from investors and give it to high-frequency traders. Now, like so many of the concerns that people have with high-frequency trading, this is a pure issue of market structure. The SEC could solve it in various ways, perhaps by getting rid of Regulation NMS entirely, or more simply by "protecting" odd lots. This recent BlackRock white paper calls for the latter solution

Comment: Interesting. Most of my trades are odd-lots. Image source

Odd lots

NYSE Turns Its Attention to Violations of Odd-Lot Transaction Rules

Excerpt:

NYSE odd-lot rules were designed to, among other things, create parity between large and small investors. The rules require orders under 100 shares to be executed by the specialist firm that handles trading in each stock at the same price as the next round-lot trade, regardless of whether the next round-lot trade is 100 or 100,000 shares. In doing so, the rules attempt to offer small investors a “leg-up” by requiring small trades (i.e., trades under 100 shares) to receive the same price as larger transactions, thereby lessening the likelihood of small orders receiving an inferior price as compared to large block orders. In addition, under NYSE rules, members have an obligation to consolidate, buy or sell a customer's odd-lot orders if the share amount of such orders exceeds 100 shares.4

Comment: An even lot is 100 shares of stock. Odd lot trading would be less than 100 shares. As a small investor I sometimes buy just 10 shares of a stock .. an "odd lot"