Merge branch 'margin-db' into margin-commands

TODO

@@ -0,0 +1,34 @@
+List of things TODO to add margin trading
+
+Files to edit
+    freqtrade/freqtradebot.py
+    freqtrade/wallets.py
+    freqtrade/data/btanalysis.py
+    configuration
+    freqtrade/commands/deploy_commands.py
+    freqtrade/commands/arguments.py
+    freqtrade/strategy
+    freqtrade/constants.py
+
+Tests
+    tests/test_persistence.pys
+    tests/test_freqtradebot.py
+
+later
+    freqtrade/commands/build_config_commands.py
+    freqtrade/commands/cli_options.py
+    freqtrade/commands/list_commands.py
+    freqtrade/commands/hyperopt_commands.py
+    config_binance.json.example
+    config_kraken.json.example
+    freqtrade/enums/selltype.py
+
+Did not look at these files
+    freqtrade/plot/plotting.py
+    freqtrade/plugins
+    freqtrade/resolvers/strategy_resolver.py
+    freqtrade/rpc
+
+Already Edited
+    freqtrade/persistence/migrations.py
+    freqtrade/persistence/models.py

docs/faq.md

@@ -136,6 +136,22 @@ On Windows, the `--logfile` option is also supported by Freqtrade and you can us
 > type \path\to\mylogfile.log | findstr "something"
 ```
 
+### Why does freqtrade not have GPU support?
+
+First of all, most indicator libraries don't have GPU support - as such, there would be little benefit for indicator calculations.
+The GPU improvements would only apply to pandas-native calculations - or ones written by yourself.
+
+For hyperopt, freqtrade is using scikit-optimize, which is built on top of scikit-learn.
+Their statement about GPU support is [pretty clear](https://scikit-learn.org/stable/faq.html#will-you-add-gpu-support).
+
+GPU's also are only good at crunching numbers (floating point operations). 
+For hyperopt, we need both number-crunching (find next parameters) and running python code (running backtesting). 
+As such, GPU's are not too well suited for most parts of hyperopt.
+
+The benefit of using GPU would therefore be pretty slim - and will not justify the complexity introduced by trying to add GPU support.
+
+There is however nothing preventing you from using GPU-enabled indicators within your strategy if you think you must have this - you will however probably be disappointed by the slim gain that will give you (compared to the complexity).
+
 ## Hyperopt module
 
 ### How many epochs do I need to get a good Hyperopt result?