- Employees are often faced with the task of valuing their
employee stock options:
a) Prior to accepting employment, when incentive
packages are offered,
b) During employment when bonuses and incentives
are offered,
c) In the event of a divorce or for estate planning
purposes, or
d) When an evaluation for risk and investment
management purposes is needed.
Employers also want to know the value of what they
are offering the employees. In addition, employers now
have to expense the fair value of options for earnings
purposes and need an accurate value to determine
the impact. They need accurate values to comply
with FASB mandates.
The question then becomes “What methods should
employees and employers use to accurately value
these employee options." And then there is the question
of whether the perceived value to the employee is
equal to the cost to the employer.
One way is to use the Black Scholes or other theoretical
valuation models. These are mathematical models,
which give theoretical prices for a particular exchange
traded option. These models incorporate such variables
as the stock price, the exercise price, the expiration
date of the option, the expected volatility, expected
dividends, and the interest rate. The models assume that
stock prices are lognormally distributed.
The Black Scholes model was created in 1973 by
Myron Scholes, Fischer Black and Bill Merton. It was
first used in the real world on the CBOE and the
Pacific Stock Exchange in 1975 and 1976 by market makers
trading listed stock options. Your writer is one of those
market makers.
In some small circles of traders and academics, it is well
known that the Black Scholes and other models are faulty
in the valuation of listed long term options as well as
employee options especially on highly volatile stocks.
Some models also seem to have problems with stock
paying high dividends.
If we do decide to use the Black Scholes model or any
model, we must then approach these models with the
understanding that these are just useful tools and not
precise instruments. Traders, who understand the models’
inaccuracies, actually trade the options at prices that are
different from the theoretical values, especially long term
options on highly volatile stocks.
Can these models be used to accurately value the employee
stock options? If so what adjustments have to be made
in doing so?
If the employee was certain to remain with his employer until
expiration of the options and was certain not to prematurely
exercise his options, there would be little need to make any
adjustments in assumptions when valuing employee stock
options compared to the assumptions in valuing listed stock
options. Although his inability to liquidate the options until
expiration certainly would cause a perceived discount in value.
Some claim the fact that employee stock options are not
transferable is a significant factor to be considered . My view
is that that idea is in error because of the availability of listed
option hedging, allowing effective transferability. The
non - transferable consideration is indeed a greater
consideration when employees are prohibited from hedging
with listed options. When employers prohibit hedging, the
perceived value to the employee is indeed diminished.
However, creative employees can find ways to hedge.
For example they can write calls on positively correlated
stocks in lieu of sellings calls on the employer stock.
FASB Mehtod
The FASB recommended evaluation method is to reduce
the nominal time to expiration to the "expected" time to
expiration. Does this not fully discount the value to the
employee when hedging is restricted? My view is that it
does but if the contract terms are extremely restrictive,
a further ajustment should be made in perceived value.
Employees do regularly terminate employment prior to
expiration with the resulting loss of options value and do
prematurely exercise their employee stock options with
substantial theoretical value forfeited. Therefore, there
must be some adjustments to certain of the assumptions
made in the pricing models when calculating the expected
costs to the employer and value to the employee.
By making these adjustments, essentially you have
adjusted the expected average cost to the employer.
That expected average cost to the employer may be more
or less than the value any particular employee may ascribe
to his options.
Better Method
We will now illustrate our valuation method for employee
stock options by using an example below:
1. Assume an employee is granted options to purchase
10,000 shares of stock in ABC company as part of a
compensation package. Those options expire ten
years after the grant day and are considered non-qualified.
2. Assume that the stock closes at $50 on grant day and
the options are exercisable at $50. Usually the exercise
price equals the market price at grant.
3. Assume the annual historical volatility (defined as the
standard deviation of returns) is .45. Assume the
“implied volatility” on the two year listed LEAP calls is .40.
LEAP calls are merely long term listed call options.
4. Assume the stock pays no dividends.
5. Assume the risk free interest rate is 3.0 % for three
month U.S. government bills and 4.3% for 10 year
U.S. government bonds.
6. Assume that the employee’s options contract has
standard provisions relating to vesting, penalties upon
early termination after vesting and the provision that the
options themselves are not transferable.
7. Assume that there are no contractual restrictions on the
employee hedging his stock options by writing listed call
options or selling stock futures or buying puts.
To calculate the employee stock options value, we can
find an appropriate options calculator at www.cboe.com or
www.numa.com or www.hoadley.net and input the
appropriate adjusted assumptions.
Those appropriate adjusted assumptions follow:
1.Stock price $50 (no adjustment necessary).Options
exercise price $50 (no adjustment necessary).
2.Volatility. Historical volatility equals .45 but the
adjusted volatility equals .37. To get this new volatility,
we used the implied volatility of the longest LEAP (.40)
and reduce that by 5 % to 7 % to get the proper assumed
volatility for the just granted employee options (Why we
use implied only and reduce the implied volatility further
is beyond the scope of this article). If the stock, whose
options are subject to valuation has no listed options or no
listed LEAP’s, one can find a similar stock (in terms of
industry and historical volatility) that does, and use that
“implied volatility”.
3.Time to expiration is reduced by 37% to incorporate
the expectations of early terminations and premature
exercises. This reduction could be more or less, depending
on the employees' expectations of longevity at the company
and their awareness of hedging strategies to avoid early
exercise. On grant day we can assume an expected expiration
time of 6.3 years (i.e.10 yrs reduced by 37%). After vesting,
the expiration day discount is reduced to 22% or less.
4.No dividends (no adjustment necessary)
5.Assume an interest rate of 3.8% (reduced from 4.3%)
---------------------------------------------------------
So what would be the value of the employee stock options
at the time of grant using the above accurate method.
CBOE gives $216,525.00 and Numa gives $218,100.00,
which for our purpose are equal.
Had we not made the corrected assumptions on volatility
and time remaining and used the historical volatility of .45
and the full 10 years to expiration, the prices would have
been CBOE $309,582.00 and Numa $310,800.00.
So there is quite a difference in pre-adjusted
and post- adjusted values.
It also must be mentioned that employees consider there
to be additional value to these employee options due to
the fact that employees receive the options without having
to report the ESOs as income for tax purposes when
granted.
The amount of additional value that is ascribed to the options
because of this factor depends on the tax bracket of the
employee and is not meant to be calculated here.
In addition it should be mentioned that the cost to the
employer in granting employee options should be considered
less than the above adjusted calculations in view of the fact
that they pay out no cash. However, the amount of that
lower cost is quite difficult to calculate. So we will not try
to calculate that amount.
Finally, this method of calculating the options value is
consistent with FASB (Financing Accounting Standards Board)
Section 123. It merely gives a more accurate calculation of
volatility and time remaining than using “historical volatility”
and using the full term to expiration.
In summary, we have demonstrated a method to calculate the
value of employee stock options. If we were to consider the
specific aspects of a particular employee options contract
(for example a prohibition on hedging) and the specifics of
each individual’s attitudes and expectations of longevity at
the company, we would surely be able to get more precise
values. That however is not the purpose of this paper.
John Olagues olagues@hotmail.com
See
http://www.wiley.com/WileyCDA/WileyTitle/productCd-0470471921,descCd-google_preview.html
http://www.brighttalk.com/dcemail_redirect/webcast/5847
http://www.brighttalk.com/webcasts/8004/attend The author, JOHN OLAGUES, is a former member of the Chicago Board Options Exchange and the Pacific Stock Exchange for over ten years. He offers a unique view of
employee stock options from a trader’s standpoint rather than from the standpoint of an accountant, compensation planner or academic. To contact JOHN OLAGUES email
olagues@hotmail.com and see
www.optionsforemployees.com.