Co-location
The practice of placing a trading firm's servers in the exchange's own data centre to minimise the time an order takes to arrive.
How it is identified
Test: the participant's matching-engine access is from within the exchange data centre rather than over a public network
Unit
qualitative
In depth
Under price-time priority, arriving first at the same price is worth money, and physical distance is measured in microseconds — hence renting rack space beside the matching engine. Exchanges must offer co-location on equal terms to all who pay, and the NSE co-location matter that ran through Indian regulation for years turned on whether access had in fact been equal. Co-location is not itself an unfair advantage; unequal access to it is. For anyone whose holding period exceeds a few seconds, the microseconds involved are irrelevant to their results.
Worked example
A co-located server may reach the matching engine in tens of microseconds, against milliseconds from a city office — a difference of perhaps a hundredfold. Over a holding period of six months, that advantage is worth nothing at all.
Illustrative figures, chosen so the arithmetic is easy to follow. Not a live price and not a valuation of any company.
Educational reference only
This entry explains what “Co-location” means. It is not investment advice and not a recommendation to buy or sell any security. Any numbers above are illustrative, not live prices, and nothing here predicts price direction or rates a stock. Consider your own circumstances and consult a SEBI-registered investment adviser before acting.