Monday, June 30, 2008

Bear Stearns in Vanity Fair

The article in Vanity Fair regarding the collapse of Bear Stearns was fascinating. Particularly for an essentially anonymous trader who was able to profit (by shorting other financial stocks as Bear went down) from their collapse. The day that Bear did the final drop (I can't pull up the ticker on any of my normal methods so I can't be sure which day it was) it was up 10 dollars at about 9 o'clock only to get beaten down to flat by 9:30 and then got smoked (pretty sure it dropped at least 25%-50% the next half hour). My only insight is that most traders just see what is happening and react.

Though the entire article is worth a read, I found the following quote particularly enlightening.
It was then that Gary Parr and the bankruptcy attorneys patiently explained that bankruptcy was actually not an option, not for a major securities firm. Changes to the bankruptcy code in 2005 would force federal regulators to take over customer accounts. All its securities would be subject to immediate seizure by creditors.
The 2005 BAPCA bill was a giveaway to credit card companies, but it seems like this statement doesn't really make sense. First, it depends on if the securities are in margin account or traditional customer accounts. Margin accounts are held in the name of the brokerage, so it makes sense that those would be able to be taken in bankruptcy. Though I'm not an expert, by any means, I would assume that this hasn't changed. Within customer accounts, SIPC protects cash and securities less than numbers only lawyers remember. So based on the statement above, the 2005 BAPCA would allow the immediate seizure by creditors of the customer's cash and securities held at Bear Stearns. To me that just means that if Bear declares bankruptcy, it would be forced to liquidate. It couldn't go into bankruptcy protection and eventually hope to emerge. The equity would be worthless. In other words, senior management would never consider bankruptcy for Bear. I could be totally mistaken, but it appears that if it weren't for the BAPCPA bill, Bear could (big assumption) have tried bankruptcy and not purchase by J.P. Morgan. I'm not an expert enough to know if this is the case, but it would be interesting to look further at the influence of this bill and the collapse of the company.

Thursday, June 19, 2008

Natural gas inventories

Natural Gas inventories were surveyed to change by 58 and came in at 57 (prior was 80). Natural Gas proceeded to fall 3% (at writing). For those who aren't traders, generally the natural gas inventories usually don't move the market enough to be worth trading (though they were three and four weeks ago), but I haven't seen such a strong, lasting move on this number when the inventories came in essentially in line. It looks like around 11 there was news (according to Briefing.com) that China would raise some prices of gasoline and crude, but this decision wouldn't affect natural gas. I guess I'm kind of at a loss to describe it.

Generally the trend is your friend, but I can't help put think that this is oversold (the front contract is at 12.72 and UNG is as 60.30 as of this writing). However, bottom picking this kind of strength on the downside can be vicious unless you are looking to hold for a long enough period. Thankfully my only position in UNG was in a play account on updown because I have been wanting to bottom pick this for at least an hour and it just keeps going down. The futures are at 12.65, down 4.3% from the open.

Edit: Looks like I was about ten minutes off the bottom. Also edited for grammar.

Monday, June 16, 2008

Volatility Smile

The Black-Scholes-Merton model makes the assumption of constant volatility. In practice, we observe something called the volatility smile. Basically, options struck at the money have less volatility if you solve for volatility in BSM than options struck far in or out of the money. This is an interesting phenomenon that finance professors like to write about and hedge funds try to exploit.

I wonder whether equity index options (in particular just b/c I know that the 10 month MA strategy works on them and they have a long history) experience different volatility smiles when above the 10 month MA or below the 10 month MA. If the volatility doesn't change, I would look to a situation where calls are cheap when the market is trending up and puts are cheap when the market is trending downwards. I imagine it would take significant work to look into this. If no one else does (let me know if you do), then I might take a stab at looking into this problem sometime within the next six months. Nevertheless, I think it is an interesting question and could present arbitrage opportunities. Volatility is traditionally higher when equity markets are below 200 day moving averages, but I wonder if it is high enough given historical volatility during these times and the small (mostly negative) returns.

Thursday, June 12, 2008

Beta and Sectors

I meant to post something about the interest rate environment and tactical asset allocation, but I haven't gotten around to it since the results aren't that spectacular. Still kind of interesting. Anyway, I've been reading Eric Falkenstein lately over at the Falkenblog and his website DefProb.

One point that he makes is that historically buying low Beta stocks has better returns than buying high Beta stocks (though there are periods of significant underperformance such as the internet bubble). I found this result interesting (risk is inversely related to returns, how could that not be interesting?) and so decided to look into a similar strategy using sectors.

I used weekly dividend adjusted data of the 9 Sector Spiders since they began at the end of '98 along with SPY. I calculated Beta vs. SPY using at least a year's worth of data and no more than 5 years worth of data. At the start of every year I ranked the Sectors on the basis of Beta and formed a high Beta and low Beta portfolio with three Sectors each. I also calculated a portfolio investing equally in each Spider to serve as comparison (SPY is market-weighted).

Over this period (from Jan. 2000 to the end of last week), the equal-weight portfolio return 2.4% annually (15.7% std), the high beta portfolio returned -.14% (20.7 std), and the low beta portfolio returned 4.3% (14.3% std).

I then calculated the 40 week (200 day) moving average and considered a signal at the beginning of the month good through the end of the month (since that is how the 10 month TAA works and I wanted it to be somewhat comparable). The results are reported below:
(After accidentally inflating the returns of the high portfolio) The results indicate that the low Beta portfolio outperforms when the market is above the 40 week moving average and slightly outperforms when the market is below the 40 week moving average which confirms the argument that Mr. Falkenstein had made (note that the Sharpe ratio is higher for the high than the low in the below 40 week, I think that the Sharpe ratio is an incorrect method of comparison when returns are below 0). That doesn't change the fact that investing when below the 200 day moving average is very risky.

CFO advisory posted yesterday regarding the sector momentum strategy (which I have covered before on this site) and noted that a significant portion of the return has been due to XLE. The low Beta portfolio included XLE from 2000 to the beginning of 2007; however, from 2007 until recently XLE return 35% annualized compared to 11% from 2000 to 2007. So I would argue that the performance of the low Beta portfolio doesn't suffer from the XLE criticism (note that I really agree with it anyhow).

Thursday, June 5, 2008

TAA and avoiding pullbacks

I should probably be studying, but this didn't take me that long to work out and was pretty interesting.

This could be considered another extension of the tactical asset allocation system developed by Mebane Faber that I have blogged about several times. The original strategy is to invest in five asset classes (US bonds, US stocks, Foreign stocks, Commodities, Real Estate) when they are greater than their 200 day moving average and commercial paper otherwise.

I modified the system slightly, maintaining the 200 day moving average requirement, but I added an additional constraint: it could not be the case that it was above the 5 month (4 and 6 have similar results) moving average and the return over the previous month was negative. The point of this was to take into account periods being overbought and then getting back in quickly. The periods above the five month that have negative prior month returns have very poor risk to reward ratios, most significantly for stocks and REITs. So making this simple addition can take a system with an 11.9% historical return with 6.8% standard deviation (.867 Sharpe at 6%) to 11.8% with 5.68% standard deviation (1.026 Sharpe). Though there is not a statistically significant difference in means, there is a significant difference in standard deviations according to an F test.

Not only is this improvement a significant, easy to implement improvement, but it is based on logic. Most trends do not continue up continuously. There tend to be pull backs. This strategy maintains the idea that the trend is your friend and attempts to stay out of a pull back if it happens two months in a row.

Note: the portfolio leveraged 50% has a 14% return with 8.5% standard deviation compared to 13.5% with 9% standard deviation for the original version. The best benefit in reducing standard deviation is in keeping the risk to reward statistics strong when using leverage.