I made a google spreadsheet for doing back testing on your own.

NOTE: The sheet is view only. To edit, make a copy.
Click ‘File’ menu, then click 'make a copy’

EXCEL HOLDING TESTER
(Note: not compatible with Desktop Excel since I use some non-traditional formulas)

You can change these variables on the tab called “BackTest”:

• $USD Amount to invest (Either one time or weekly)
• Top N coins (i,.e. 10 vs 8 vs 20)
• Starting week & Ending week (for 1-time investment, make the weeks the same)

with those variables, you can simulate:

• a 1 time investment (i.e. $10,000 first week of Jan 1 into top 8 or 10 coins)
• a weekly investment (i.e. $20 per coin into top 10 coins to invest $10,400/year)
• an investment last month, last week, etc

Also has Chart to show portfolio value

Going for a one-time investment or a weekly investment?

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The sheet will help precalculate the number of shares to buy to stay on track with your investment amount

Here are a few things you can try:
One-Time Investment @ $10,000
Top 20, Invest $500, Start Week 1/1/2017, End Week 1/1/2017
Top 10, Invest $1000, Start Week 1/1/2017, End Week 1/1/2017
Top 8, Invest $1250, Start Week 1/1/2017, End Week 1/1/2017
Top 8, Invest $1250, Start Week 7/31/2017, End Week 7/31/2017

Dollar Cost Average Investing @ $10,400/year
Top 20, Invest $100, Start Week 1/1/2017, End Week 8/27/2017
Top 10, Invest $100, Start Week 1/1/2017, End Week 8/27/2017
Top 8, Invest $100, Start Week 1/1/2017, End Week 8/27/2017

This sheet is about the idea of investing and holding afterwards

If you see any mistakes, or improvements, let me know!

NOTE: The sheet is view only. To edit, make a copy.
Click ‘File’ menu, then click ‘make a copy’

Have fun with it!