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- actually I'm just make most of this **** up so its probably all wrong)
(give or take a bourbon or two)
Yep in theory but in real life only if the bet size is the same dollar amount each time. As soon as you start talking fractional size of a portfolio for position sizing or any dynamic position size for that matter you better start thinking geometric rather than arithmetic or the expectancy calculation isn't going to tell you diddly squat about real life. Individual size, and sequence of every win/loss skews the real life expectancy from theory. (as the extreme analogy demonstrates)The expectancy is as stated
The expectancy is as stated and the problem is that LTI is investing too much on each coin toss.
The Kelly Criterion shows the optimum bet size for this proposal is to "invest" no more than 20% on each toss.
K% = 0.6 - [0.4 / AW/AL] = 0.6 - 0.4 = 0.2 = 20%
In practice the Kelly calculation can produce large draw downs, even using the correct position size, but as LTI sets off metal detectors at airports he will be able to handle that and profit handsomely if he is allowed to invest more wisely.
Hi,
Been playing with individual position size (1% of capital), portfolio position size, portfolio heat at any time in the market (% amount at risk at anyone time regardless of the number of positions based on stops and an error factor for slippage/gap downs) and win/loss ratio while counting for a large run of loses in a row and size of potential draw down.
It would be great if anyone could elaborate on how they calculate how much is at risk if there is a wipe out day and stops at hit. What % of capital.
Another question is if the bet was :
LTI had a win loss ratio of 50%, coin toss
LTI was paid 100% of his capital for each win
The man only 50% of LTI's capital a win
Would LTI be better off?
HNY QFThanks DS for your nice lesson in stats, risks and expectancies.Any feeling as tho the market general situation?
While not close yet at the time of this post, Wall Street still going downward, bringing the AUD along.
Oil and gold +- even when seen in AUD.
a needed drawdown or a more profund issue with the debt related to oil (and for Oz gas investment)
Does the "oil debt"and ramifications worries you?; I have no real idea which banks are exposed (here and O/S) and that info looks hard to get: exposure of banks to oil?
Please note that at this price i am actually bullish mid term for oil: I expect serious issues in S.A. coming from within and oil will not stay where it is when RIAD is in flamme, especially as I see probable a conflict with Iran triggered by the royals in S.A. to create internal diversions for their populace when things turn ugly.
Oil at 33$ today just need to go to $50 which is still quite low to create a 50% gain, I can wait 5 years for that and my return would be quite decent overall, so I see my risk more in the actual instrument I use (oil index OOO)
HAve a nice week end
FT reports that we are at peak gold supply for the current cycle.
I guess I am one of only a few on the forum who even consider it interesting that we are at "peak gold supply" from mining and yet the inventory of physical gold has been drained from the bullion banking system (of which LBMA and GLD make up easily to two largest reserves) nonstop for 4 years.
The monetary authorities have largely been the prime force holding up the economy and keeping financial burdens in check. Enormous faith has been placed in them. What if it isn't justified? Alternatively, what if it is justified, but they've now exhausted their credible tool set*? Yet the markets continue to react as if there is still juice in this strategy. Hmmm.
Risk parity is a concept which was brought into popularity by Ray Dalio of Bridgewater Associates, the world's largest hedge fund manager. The idea has evolved to, kinda sorta, build a portfolio whose main components had equal risk contributions (proportion of overall volatility).
(from http://www.berkshirehathaway.com/letters/2014ltr.pdf)Stock prices will always be far more volatile than cash-equivalent holdings. Over the long term, however, currency-denominated instruments are riskier investments — far riskier investments — than widely-diversified stock portfolios that are bought over time and that are owned in a manner invoking only token fees and commissions. That lesson has not customarily been taught in business schools, where volatility is almost universally used as a proxy for risk. Though this pedagogic assumption makes for easy teaching, it is dead wrong: Volatility is far from synonymous with risk. Popular formulas that equate the two terms lead students, investors and CEOs astray.
...
It is true, of course, that owning equities for a day or a week or a year is far riskier (in both nominal and purchasing-power terms) than leaving funds in cash-equivalents. That is relevant to certain investors — say, investment banks — whose viability can be threatened by declines in asset prices and which might be forced to sell securities during depressed markets. Additionally, any party that might have meaningful near-term needs for funds should keep appropriate sums in Treasuries or insured bank deposits.
For the great majority of investors, however, who can — and should — invest with a multi-decade horizon, quotational declines are unimportant. Their focus should remain fixed on attaining significant gains in purchasing power over their investing lifetime. For them, a diversified equity portfolio, bought over time, will prove far less risky than dollar-based securities.
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