I "created" 4 ETFs in Nov 2020. Each had < 30 stocks.
Results
1. Cannabis +127%
2. Genomics +49%
3. Solar + 46%
4. eCommerce +36%
What I learned:
1. 3-4 stocks drove over 75% of the gains in each ETF
2. Equal Cap beats Weighted Cap
3. Equal $ is ok

Tickers in solar:
$BEP
$SPI
$JKS
$ELLO
$ARRY
$AQN
$SSO
$ABB
$CWEN
$FSLR
$VVPR
$SEDG
$HASI
$NOVA
$AY
$ALB
$RUN
$CSIQ
$AZRE
$ENPH
$SPWR
$TSLA
$SUNW
$DQ
$BEEM
$MAXN
$SOL

Tickers in Cannabis
$GWPH
$SRNE
$IIPR
$SMG
$CGC
$SSPK
$CRON
$GTEC
$ACB
$GRWG
$VFF
$APHA
$TLRY
$SNDL
$HEXO

Tickers in Genomics
$MCRB
$PSTI
$ACCD
$VCYT
$TAK
$REGN
$ARCT
$BLI
$VRTX
$NVS
$CGEN
$TMO
$INCY
$NVTA
$PSTG
$TDOC
$ILMN
$IONS
$EXAS
$CERS
$TXG
$CLLS
$GH
$IOVA
$SDGR
$CDXS
$ADPT
$RPTX
$PHR
$NSTG
$SURF
$CDNA
$CSTL
$PSNL
$ONVO
$SYRS
$TWST
$CRSP
$EVGN
$FATE
$NTLA
$EDIT
$PACB
$BEAM

Tickers in eCommerce
$BZUN
$BABA
$AMZN
$JD
$OSTK
$EBAY
$SHOP
$PDD
$FTCH
$W
$SE
$ECOM
$MELI
$ETSY
$CHWY
$JMIA
$REAL
$SFIX

Notes:
1. The stocks are all ranked from "Worst" performing to "Best" - i.e. Bottom of the list tickers are best
2. Equal Cap = put same $ in large, mid and small cap
3. Equal $ = put the same amount of money in each stock within "ETF"

My "Worst" performing ETFs
1. Lidar (13%)
2. The 35 MegaCap stocks 3.5%
3. Fortune 100 of the future list 4.5%
4. Real Estate Tech 4.6%