pz1975
Active Member
To add to the discussion of IV changes pre- and post-ER, I just looked up the current IV (day of ER after close) for ATM (200) calls between this week and Jan2016.
Time to expiry - IV
2 days (May 9) - 1.69
1 week (May 17) - 0.90
2 weeks (May 23) - 0.84
3 weeks (May 30) - 0.73
6 weeks (Jun21) - 0.61
4 months (Sept20) - 0.53
8 months (Jan2015) - 0.50
1 year,8 months (Jan2016) - 0.47
I will do this again post-ER tomorrow or Friday and compare the relative IV changes pre- and post-ER.
To follow-up on the above, here were the closing IV values on Friday for ATM (currently 180) calls. I obviously chose 180 instead of 200 to keep the comparison the most valid (ie. as close to ATM as I could get).
Time to expiry - IV
0 days (May 9) - 1.66
1 week (May 17) - 0.48
2 weeks (May 23) - 0.50
3 weeks (May 30) - 0.47
6 weeks (Jun21) - 0.47
4 months (Sept20) - 0.53
8 months (Jan2015) - 0.48
1 year,8 months (Jan2016) - 0.46
These results were pretty interesting. The May 9 calls have a similar IV as pre-ER. My thought here is that immediately after ER (Thursday morning), they probably did drop (sorry I did not check) to levels on the 0.50ish range, but then spiked up again in the last minutes before expiry due to heavy trading as traders sought to offload them.
All the other expiry dates from 1 week out to the farthest out LEAPS dropped post-ER to very similar IV numbers (0.46-0.53), while pre-ER options 4 months out to 1.5 years out had similar IV values pre- and post-ER. Inside 4 months however, is where the big IV drops happen post-ER, with the amount of drop increasing (as expected) as the time to expiry date shortens. What I have learned (and knew intuitively before doing this) is that it is very risky to 'play' an ER using options less than 3-6 weeks out (and especially 2 weeks out or less) since the IV drop alone will result in significant losses (or less gains).