Evaluating Crypto Rebalancing Strategies After Trading Costs
Summary
The document discusses how to assess a cryptocurrency portfolio rebalancing strategy based on mean reversion, especially when frequent trading costs overwhelm attractive backtest results. Its example compares hourly and daily backtests under different fee assumptions. The response attributes the hourly strategy’s sensitivity to its large number of rebalances: potential rebalancing gains accumulate with variance captured, while costs rise with each trade.
It recommends examining results per rebalance, comparing the price movement captured with the round-trip cost, rather than relying only on the aggregate equity curve. It also suggests replacing fixed-time rebalancing with threshold bands so trades occur when portfolio weights drift materially from targets. The example’s suggested bands are illustrative, not established as optimal. Finally, doubling fees is only a rough slippage proxy: spreads in thin altcoin pairs may widen during volatile periods, so historical spread data for the traded pairs would improve cost estimates. The strategy’s limited history also constrains confidence in its backtest.
Key ideas
- Frequent scheduled rebalancing can generate enough trading costs to erase the gains seen before fees.
- Measure captured price movement against round-trip costs at each rebalance, as well as reviewing portfolio-level returns.
- Threshold-based rebalancing can reduce unnecessary trades by waiting for meaningful weight drift.
- A fixed fee multiplier may understate slippage when spreads widen in thin markets or volatile periods.
- Limited historical data makes it harder to establish that backtested performance will persist.
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# How to ascertain/establish certainty of a portfolio rebalancing strategy? # How to ascertain/establish certainty of a portfolio rebalancing strategy? I created a portfolio rebalancing strategy, that I am currently paper trading with. It is, primarily, based on mean-reversion principle with a few rules in place, and geared towards cryptocurrencies, in general. I double the commission to account for slippage as well as when rebalancing I first sell all assets I am holding and then, buy them even if same. This adds a few pips of random slippage as well, at the least. Here are a few plots I obtained from this strategy in backtesting. I used `1h` as well as `1d` ticks from Bittrex. `1d` timeframe backtesting result with a `0.5%` (0.25% bittrex + 0.25% slippage) commission fee: `1hr` timeframe with `0` fee: with 0.2% fee (binance 0.1% plus 0.1% slippage): with 0.5% fee (bittrex 0.25% plus 0.25% slippage): Now, since the chosen domain does not provide extensive history, I am unable to test this strategy on a longer timeframe. And, therefore, I would like to know how I can ascertain that the strategy is indeed useful? I, particularly, would like the 1hr timeframe equity curve, but adding commission there ruins everything. ## Answer by Valerii Sakara (score 0) https://quant.stackexchange.com/a/85763 The pattern in your four charts is a clean signature, not a fluke: at 1h rebalancing, you're trading constantly, so the number of round-trips is enormous. The volatility-pumping/rebalancing premium scales roughly with realized variance captured between rebalances, but transaction cost scales linearly with the number of rebalances — at 1h that's ~24x more trades than at 1d for capturing much the same total variance. So going from 0% to 0.2% to 0.5% doesn't erode the edge proportionally, it erodes it combinatorially: you're paying the same fee 24x more often against a shrinking per-trade gain. Two things worth checking before writing this off (or trading the 1d version live): - Compute edge-per-rebalance directly instead of reading the aggregate equity curve. For each rebalance event, log the raw price move captured versus the round-trip cost paid at that event. If the median edge-per-rebalance is smaller than roughly 2x your assumed cost-per-rebalance, the strategy is bleeding on a typical trade and only surviving on tail events — that's a fragile edge, not a real one, regardless of what the cumulative curve looks like. - Switch from scheduled (every-hour) rebalancing to threshold/band rebalancing — only trade when an asset's weight drifts past e.g. ±3-5% of target, instead of on a fixed clock. This is standard in the volatility-pumping literature specifically because it decouples trade frequency from time and ties it to actual drift, which is what you're trying to harvest. You'll capture most of the premium at a fraction of the round-trips, and it'll tell you honestly whether the edge survives realistic costs — instead of comparing several fee assumptions against the same over-frequent schedule. One more thing worth double-checking: doubling the fee is a clean way to approximate slippage, but on thin alt pairs the real bid-ask can blow well past a flat multiplier during exactly the high-volatility windows a mean-reversion signal is trying to catch. That's usually where a backtest's assumed slippage diverges hardest from what a live order book would have actually given you — worth pulling real historical spread data for your specific pairs rather than assuming a constant.
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