Artificially Creating Market Volume

Wash Trading

An illegal stock trading practice where an investor simultaneously buys and sells shares in a company through two different brokers.

This increases the activity in the stock and gives the impression that "big news" is about to come out

Painting the Tape

The illegal practice in which traders buy and sell a specific security among themselves, creating the illusion of high trading volume and significant investor interest, which can attract unsuspecting investors who might then buy the stock and enable the traders to profit.

Oct 20 NYSE SPY "Mispricing"

Bloomberg:
NYSE Software Glitch Spurs $7.9 Billion Misprice in S&P 500 ETF

A system upgrade at Arca triggered what appeared to be a 9.6 percent plunge yesterday in an exchange-traded fund that tracks the Standard & Poor’s 500 Index, a drop that would have erased $7.9 billion from one of the most popular securities in the U.S. Data published by the electronic venue at 4:15 p.m. New York time showed the SPDR S&P 500 ETF Trust at $106.46, compared with its opening level of $117.74.

The prices were later voided and the closing price updated to $118.54, up 0.7 percent, exchange officials said.

usd-jpy - Japan and the Trillion Dollar Question

Japan intervenes in currency market to weaken yen for first time since 2004
Shino Yuasa, On Tuesday September 14, 2010, 11:18 pm EDT
Dollar fades after durable-goods, home-sales data. Greenback at lowest versus Swiss franc since March 2008
Sept. 24, 2010, 3:33 p.m. EDT
Yen falls against dollar, euro after Japan intervention
AFP - 15 September 2010
Japan moves to combat rising yen
15 September 2010
Japan intervenes in currency markets to weaken yen
The Irish Times - Thursday, September 16, 2010
Yen sinks on Japan intervention; global stocks drift
By Walter Brandimarte - NEW YORK | Wed Sep 15, 2010 6:11pm EDT
Japan suspected of yen intervention, doubts arise
By Masayuki Kitano and Yoshiko Mori - TOKYO | Fri Sep 24, 2010 9:02am E