The Tokyo Stock Exchange reopened under its current Japanese name on May 16, 1949, pursuant to the new Securities Exchange Act.
The TSE runup from 1983 to 1990 was unprecedented, in 1990 it accounted for over 60% of the world's stock market capitalization (by far the world's largest) before falling precipitously in value and rankings today, but still remains one of the 3 largest exchanges in the world by market capitalization of listed shares.
The current TSE building was opened on May 23, 1988, replacing the original TSE building from 1931, and the trading floor of the TSE was closed on April 30, 1999, so that the exchange could switch to electronic trading for all transactions. A new facility, called TSE Arrows (ja:東証アローズ Tōshō Arrows?), opened on May 9, 2000. In 2010, the TSE launched its Arrowhead trading facility. 
In 2001, the TSE restructured itself as a stock company: before this time, it was structured as an incorporated association (ja:社団法人 shadan hōjin?) with its members as shareholders.
The exchange was only able to operate for 90 minutes on November 1, 2005, due to bugs with a newly installed transactions system, developed by Fujitsu, which was supposed to help cope with higher trading volumes. The interruption in trading was the worst in the history of the exchange. Trading was suspended for four-and-a-half hours.
During the initial public offering of advertising giant Dentsu, in December 2001, a trader at UBS Warburg, the Swiss investment bank, sent an order to sell 610,000 shares in this company at ¥1 each, while he intended to sell 1 share at ¥610,000. The bank lost £71 million.
During yet another initial public offering, that of J-Com, on December 8, 2005, an employee at Mizuho Securities Co., Ltd. mistakenly typed an order to sell 600,000 shares at ¥1, instead of an order to sell 1 share at ¥600,000. Mizuho failed to catch the error; the Tokyo Stock Exchange initially blocked attempts to cancel the order, resulting in a net loss of US$347 million to be shared between the exchange and Mizuho. Both companies are now trying to deal with their troubles: lack of error checking, lack of safeguards, lack of reliability, lack of transparency, lack of testing, loss of confidence, and loss of profits. On 11 December, the TSE acknowledged that its system was at fault in the Mizuho trade. On 21 December, Takuo Tsurushima, chief executive of the TSE, and two other senior executives resigned over the Mizuho affair.
On January 17, 2006, the Nikkei 225 fell 2.8%, its fastest drop in nine months, as investors sold stocks across the board in the wake of a raid by prosecutors on internet company livedoor. The Tokyo Stock Exchange closed early on January 18 due to the trade volume threatening to exceed the exchange's computer system's capacity of 4.5 million trades per day. This was called the "livedoor shock". The exchange quickly increased its order capacity to five million trades a day.
The exchange's normal trading sessions are from 09:00 a.m. to 11:30 a.m. and from 12:30 p.m. to 3:00 p.m. on all days of the week except Saturdays, Sundays and holidays declared by the Exchange in advance. The exchange is closed for the following holidays: New Year's Day, Coming of Age Day, National Foundation Day, Vernal Equinox Day, Shōwa Day, Constitution Memorial Day, Greenery Day, Children's Day, Marine Day, Respect for the Aged Day, Autumnal Equinox, Health and Sports Day, Culture Day, Labour Thanksgiving Day, and The Emperor's Birthday.
The London Stock Exchange (LSE) and the TSE are developing jointly traded products and share technology, marking the latest cross-border deal among bourses as international competition heats up. The TSE is also looking for some partners in Asia, and more specifically is seeking an alliance with the Singapore Exchange (SGX), which is considered as becoming a leading financial hub in the Asia-Pacific region. Recently[when?], some rumors close to the deal suggest that the TSE is preparing for a takeover of the SGX, or at least take a major stake, in the first semester of 2008. The TSE has already acquired a 5% stake in the SGX as of June 2007, deemed to be only the beginning of greater participation.
In July 2008 the London Stock Exchange (LSE) and the TSE announced a new joint venture Tokyo-based market, which will be based on the LSE's Alternative Investment Market (AIM).