Wednesday, 14 March 2012

Warrants trading: What you need to know

Structured Warrants – Gearing & Greeks
In this article we will look at gearing factor and sensitivity coefficients – the Greeks which measure change in warrant value via change in other variables. 

Gearing & Effective Gearing: Structured warrants cost only a fraction of their underlying shares. They provide holders with greater exposure to price movements as they generally rise and fall more steeply in percentage terms. If a warrant is priced at RM0.30, and the underlying share is trading at RM1.50, the gearing is 5 times. The price of one warrant offers exposure to 5 shares. In bull markets, warrants will always be among the top risers and the opposite holds true in bear markets.

The definition of gearing is: 
Gearing = Share Price / Warrant Price (adjusted by exercise ratio) 

The following chart plots the relative price movements of a call and put warrant against corresponding movements in the underlying share price. Note the percentage change in the value of the underlying share compared with the value change in the call warrant and the put warrant. During a 3-month period, the underlying share price falls by 10% (at Point A) and increases by 8% (at Point B) - share price varies over an 18% range. In contrast, the call warrant fluctuates within a 75% range, while the put warrant fluctuates within an 80% range but in an opposite direction to the call. 
Gearing decreases as the share price increases. 

Delta & Gamma: Delta refers to the rate of change of warrant price for a given change in the underlying share price. For call warrants, the delta will fall between 0 and 1; for puts it will be between 0 and -1. At 0, the warrant is impartial to any moves on the underlying share. At 1, the warrant is expected to move sen-for-sen with the underlying share. Typically, at-the-money warrants will have a delta of 0.5. As the warrant moves in-the-money, the delta will approach 1. 

The most savvy of traders will aim for medium-delta warrants, in the range of 0.4 to 0.5. Any delta too low will denote an out-of-money warrant with strike too far away. 

The delta is a constantly changing number. The rate of change of delta is known as the gamma. One could visualise delta as the speed of the warrant, and gamma as the acceleration. The gamma simulates the changes on the warrant price for different underlying share price. Any move on the underlying share will move the delta higher, as with the gamma. 

Vega: Vega measures the sensitivity of warrant price to change in volatility. Vega is the highest for at-the-money warrants, and tends to be higher for longer-dated warrants. 

With several issuers issuing warrants on the same shares, the belief is that investors and traders should focus on the warrant with the lowest implied volatility. This is only true if the issuers will buy back their warrants at a proportionate volatility level. An example would be buying a warrant at an implied volatility of 45%, which the issuer buys back at 42% versus buying a warrant at a volatility of 40% that is bought back at a volatility of 30%. 

Theta: Also known as time decay, Theta is expressed in terms of sen or percentage per week (or per day closer to expiry). Eventually, the warrant will need to lose the time value entirely. But theta is not linear to time – it will get proportionately larger as it approaches expiry. 

Rho: Rho measures the sensitivity of warrant prices to changes in interest rates. However, the level of interest rates, as a variable, is likely to influence neither warrant pricing nor trading decision making process. 

Final Thoughts: The Greeks do not help answer which warrant to buy. However, they are reliable forecasting tools on the changes in warrant prices versus the underlying share price movements. 


Warrants trading: What you need to know  Parameters & Variables of Structured Warrants

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