What's the wrong with the Yahoo chart showing the wrong price at different times?

Question

The following are the charts from Google and Yahoo Finance for the AAPL stock.

A few questions regarding the chart and the prices:

1. The Google chart shows the price of 316.49 at 9:30 AM while Yahoo shows 315.78. What is the reason behind this discrepancy?
2. Does a stock enters the Market with it's pre-market price? In this case the pre-market price was 316.27 at 9:29 AM and enters the market at 9:30 AM with the same price? Or it can be the price after the first trade at 9:30 AM?
3. The Previous Close for AAPL stock was at 315.24. Did the price increase from 315.24 to 316.49 happen when the traders bought more stocks after and pre market? Does NASDAQ Futures indicate those trades? In this case NASDAQ Futures should show high.
4. Does the 3.49 price increase is calculated from the previous close on 3/16/2020 which is 315.24?
5. Is there a free chart like Yahoo Chart that shows the streaming traders activity of buying and selling?

Google Chart:

Yahoo Chart:

Answer 1

The reason for the price discrepancy:

• A) Yahoo has bad data

• B) Google has bad data

• C) All of the above

Web sites like Yahoo report regular hours trading info (Open, High, Low, Close, Volume). Some may also provide secondary information like current price during after hours.

If a broker does not offer after hours trading there will be a similar gap from yesterday's close to today's open.

A broker who offers after hours trading will have more continuity of price with after hours trading ending at 8 PM EST and resuming at 6 AM EST. A higher service broker will not only print the trades as they occur but will also offer you the choice of regular hours trading graphs or those that include after hours trading as well.