Metrics that indicate the demand for bitcoin that exists.
Greater demand will mean an increase in the price of BTC and lower demand will indicate a decrease in the price.

ETF BTC Flow
The daily flows and aggregates of Bitcoin of the ETF, Blackrock (IBIT), The Grayscale Bitcoin Trust (GBTC), Fidelity (FBTC), Ark Invest /21Shares (ARKB), Bitwise (BITB), Franklin (EZBC), Investco / Galaxy (BTCO), Vaneck (HODL), Valkyrie (BRR) and Wisdomtree (BTCW).

NVTS (Dynamic Range NVT Signal)
It is the PE (Price Earning Ratio) ratio of Bitcoin, which arises from dividing the dollar value of on-chain transactions by the market capitalization.
The number of unique Bitcoin addresses that sent or received transactions.

Active Addresses
The number of unique Bitcoin addresses that sent or received transactions. Only how you activate addresses that made successful transactions are taken into account.
This is a metric that shows the activity in the Bitcoin network.

Open Interest Futures
Bitcoin open interest is the total number of Bitcoin futures or options contracts outstanding in the market.
It is a measure of the amount of money invested in Bitcoin derivatives at any given time.

Fear and Greed
The Bitcoin Fear and Greed Index is a metric used to gauge the overall market sentiment surrounding Bitcoin and, by extension, often the broader cryptocurrency market.
Created by Alternative.me, the index gives a daily score on a scale from 0 to 100, where lower scores indicate "Fear" and higher scores indicate "Greed.

Google Trends
Google Trends provides data on search interest in Bitcoin giving insight into the search popularity of BTC around the world.

BGeometrics Demand Index
The chart with the historical data of the Demand Index along with the price of bitcoin.