Have gotten a few questions of why I'm doing my challenge in BTC and not in USD value or another fiat. Will try to explain my thinking here.
I believe in the long term viability and growth of Bitcoin and the technologies in the crypto space. I feel Bitcoin's value will only continue to grow in value versus USD and other fiat currencies. Yes, we've had a significant drop from the all-time highs. Yes, I've used fiat to purchase more BTC on the way down to dollar cost average down. In the end, at this point, I don't worry about the USD value of my BTC, because I'm not looking to cash out into fiat. IF I was, then I'd worry about the current BTC/USD value.
As BTC continues to increase in value against fiat, my current goals are to continue growing the amount of BTC I have. With more BTC, I'll have more fiat in the future. While I could stop trying to grow the amount of BTC I have and just hodl, knowing that the fiat value will continue to increase. But I'd rather take advantage of certain situations that'll allow me to grow the amount of BTC.
The other thing is that I get to see the real percentages of how I'm doing with my investments and trades.
BTC is fixed, in the sense that I either gain or lose BTC. If I make no trades, the BTC amount will always be the same. With fiat, it's variable when tied to BTC. If I make no trades and the USD value grows due to BTC/USD growth, I personally have a false sense of gains. If I gain more BTC and the BTC/USD value grows at the same time, I will also personally have inflated gains due to both variables gaining. I'd rather have something fixed that I can compare to.
Here's an example comparison of BTC and USD growth with the Challenge portfolio. The BTC/USD value is from GDAX and it's on the hour close (Asia time). I took the time of the portfolio snapshots.
BTC/USD Value on GDAX:
Start: April 4, 2018 at 4pm - $7,300
Latest: April 20, 2018 at 10am - $8,330
Starting portfolio BTC amount: 0.10574079 (I included the losses of the three coins to get the actual starting BTC amount)
USD Value if BTC/USD is $7,300 (4/4/18 at 4pm) = $771.91
USD Value if BTC/USD is $8,330 (4/20/18 at 10am) = $880.82
You can see BTC/USD grew 14.11% ($880.82 / $771.91) alone with no change in BTC amount.
Latest portfolio BTC amount: 0.17548910
USD Value if BTC/USD at $7,300 (4/4/18 at 4pm) = $1,281.07
USD Value if BTC/USD at $8,330 (4/20/18 at 10am) = $1,461.82
Real BTC Gains: 65.96% (0.17548910 BTC / 0.10574079 BTC)
USD Gains if Fixed BTC/USD of $7,300: 65.96% ($1,281.07 / $771.91)
USD Gains if Variable BTC/USD from $7,300 to $8,330: 89.38% ($1,461.82 / $771.91)
You can see that the real BTC gain is 65.96%. If the BTC/USD value was fixed, you'll get the same USD Gains of 65.96%.
BUT if you use a variable BTC/USD value, you'll see 89.38% gains in your USD. That 23.42% extra gives me a false sense that I'm doing better in my challenge than I actually am.
Yes, you can exchange more USD for the amount of BTC you have. But if you believe in the long term growth of BTC/USD value anyways, it's a given you'll be able to exchange more USD for the amount of BTC you have.
For a challenge like what I'm doing, I don't care so much about the daily changes of BTC/USD. I just want to know how much I'm growing my portfolio in BTC terms. That'll show how good or bad of a trader/investor I am. In the end, if I have more BTC, I already know that I have more USD.
Hope that makes sense!
Note: I noticed my BTC percentage gains are off from what the Delta app is telling me. I'm not going to fuss with it though at this point. I have no clue why it's off. I haven't changed anything. As long as it's consistently starting from the same amount, it's fine. I ran a calculation and a 71.28% gain would mean I started from 0.1024574 BTC. So technically, the percentage gains got inflated along the way due to the starting BTC value decreasing somehow. Either way, the current BTC amount hasn't changed.