Greeks (finance)

In mathematical finance, the Greeks are the quantities representing the sensitivity of the price of derivatives such as options to a change in underlying parameters on which the value of an instrument or portfolio of financial instruments is dependent. The name is used because the most common of these sensitivities are denoted by Greek letters (as are some other finance measures). Collectively these have also been called the risk sensitivities,risk measures or hedge parameters.

Use of the Greeks

The Greeks are vital tools in risk management. Each Greek measures the sensitivity of the value of a portfolio to a small change in a given underlying parameter, so that component risks may be treated in isolation, and the portfolio rebalanced accordingly to achieve a desired exposure; see for example delta hedging.

The Greeks in the Black–Scholes model are relatively easy to calculate, a desirable property of financial models, and are very useful for derivatives traders, especially those who seek to hedge their portfolios from adverse changes in market conditions. For this reason, those Greeks which are particularly useful for hedging—such as delta, theta, and vega—are well-defined for measuring changes in Price, Time and Volatility. Although rho is a primary input into the Black–Scholes model, the overall impact on the value of an option corresponding to changes in the risk-free interest rate is generally insignificant and therefore higher-order derivatives involving the risk-free interest rate are not common.

Delta Cafés

Delta Cafés (Portuguese pronunciation: [dɛɫtɐ kɐfɛʃ]) is a Portuguese coffee roasting and coffee packaging company headquartered in Campo Maior, Alentejo. The company was founded in 1961 and is among the top market leaders in the Iberian Peninsula. The company belongs to Nabeiro Group, the personal conglomerate of its founder Rui Nabeiro, which include interests on agribusiness, agriculture, real estate, hotels, and other services.

History

Delta Cafés was founded by Rui Nabeiro in 1961 in the town of Campo Maior, Alentejo in a small 50-m² warehouse, which could only handle two 30 kg roasters. In 1998, the Nabeiro/Delta Cafés Group was restructured and gave rise to 22 companies organized into strategic areas, with turnover of approximately €160 million. In the 2000s, it become the market leader for coffee in Portugal, with a market share of 38%. It has 47,000 direct retail clients (among the largest of which is Sonae, a leading Portuguese retailer) and 3,000 employees. Also in the 2007, Delta Cafés launched its own espresso products, Delta Q, based on a proprietary system of single-serving "capsules" containing ground coffee and rooibos, and specialized machines to brew espresso from the contents of the capsules in a similar way to that of Nestlé's Nespresso brand portfolio.

Delta (video game)

Delta is a horizontally scrolling shooter computer game originally released for the Commodore 64 by Thalamus Ltd in 1987. It was programmed by Stavros Fasoulas and the music was written by Rob Hubbard. The menu-music is based on the theme of Koyaanisqatsi by Philip Glass and the in-game-music is based on Pink Floyd's On the Run. The game was also released for the ZX Spectrum in 1990 as Delta Charge.

The game was released as Delta Patrol in the United States by Electronic Arts for its Amazing Software line of action-oriented software programs, in 1987 on the Commodore 64.

The player controls a spaceship and gains power-up points by destroying formations of enemies. Some enemy formations instead subtract power-up points for the player, so the player must take note of which formations to destroy. Periodically blocks containing the power-ups (higher speed, faster rate of fire) appear and the player can pick one of them up: The more points the player has collected, the more powerful are the power-ups that can be chosen. Unavailable power-ups are gray and kill the player if he flies into them, making them part of the obstacles in the game. The effects of the power-ups are lost over time and must therefore be regained. The player gets a choice between in-game music or in-game sound effects. There is also a high score table but no way to save it when the game is turned off.