Altruists who don't care too much about risk (and young people in general) should plausibly use leveraged investing. What's the best way to get leverage?
- Margin borrowing seems like the default solution. I might try it if there's nothing better.
- Theoretically options could be used, but I'm unsure whether they work in practice.
- Supposedly futures offer massive leverage, but I haven't explored the details, and they seem hard to trade yourself. I'd like something I can just buy and hold for a long time.
- Something else?
Ideally, there should be a fund that you just buy into to get leverage, with someone else handling the details. But leveraged ETFs don't work because they're optimized for day trading and as a result lose money for buy-and-hold investors.
You can exactly simulate a leveraged position using a leveraged ETF by increasing your position whenever the market goes down and decreasing it whenever the market goes up. If you think that price changes between periods are a martingale, then it's pretty obvious that changing your investment ilike this won't increase your net profits.
This strategy is only a good idea if the market is more likely to go up after it goes down. In practice, this has been true on some time scales, while the reverse is true on others. In theory, this shouldn't predictably happen, because a savvy investor can make money. But whether or not you think this is true, there are more direct ways to earn money if you think that you can predict which way the market will move.
Note that one reason that this strategy looks good on paper is that it's a thinly-veiled version of the martingale, taking place on a log scale. If you keep doubling down every time you lose, then you will either win a bit or you will lose everything. I.e., you can keep borrowing more to avoid a margin call, but if you do that it just makes an eventual margin call worse.
It's pretty easy to do the math for a GBM and log utility. I don't know a reference. An easy way to think about it is to consider a leveraged ETF that rebalances every day vs. every other day. Both have losses that depend on volatility. Which one experiences more volatility on average? The answer is that they are basically the same, because the volatility over two days is double the volatility over one day: half of the time the moves are in opposite directions and the volatility is 0, and half of the time they are in the same direction and the reallized volatility is 4x. Similarly if we go up to every 4 days, or every 8 days. Your leveraged positioan is just rebalancing every few years.
I haven't encountered much of this (at least not at 2x leverage), most people caution against the risk of a margin call during a downturn.
It's going to take me a while to grok all of your arguments. :)
This is a key point that I don't understand. It seems like the two are different, as the following example shows.
Leveraged ETF: Buy a 2:1 leveraged ETF for $50. They borrow $50. They buy $100 in stocks. During the day, stocks increase 10%, so that the value is $110. To restore a 2:1 leverage ratio, the fund borrows anothe... (read more)