Trading Statistics

SPY Trading Statistics
SPDR S&P 500 Trust ETF (NYSE: SPY)

DIA Trading Statistics
SPDR Dow Jones Industrial Average ETF (NYSE: DIA)

QQQ Trading Statistics
PowerShares QQQ Trust ETF (NASDAQ: QQQ)

Important Note on Historical Price Data Accuracy:

We understand that comparing chart data across different platforms can sometimes reveal minor inconsistencies in historical prices, including daily highs, lows, and closing values. This is a common phenomenon in financial data and is typically due to variations in how data is sourced, processed, and adjusted by different providers. We aim for the highest possible accuracy using data from our financial API, but these inherent differences can lead to discrepancies.

Here are the primary reasons why historical data may vary:

Data Sources and Vendors
Financial data providers aggregate information from numerous sources such as different exchanges, trading platforms, and data vendors. Each vendor may collect data through various trading venues or even generate their own OHLCV (Open, High, Low, Close, Volume) data from raw tick-by-tick trades. For example, some historical data sets widely available online (like older versions from Yahoo, which reportedly used vendors like Hemscott) may have sourced data differently than those used by other platforms (like Google, which has sourced from Deutsche Börse). A provider might also switch vendors or data sources over time, leading to inconsistencies between older and newer data points on their own platform.

Bid vs. Ask Prices
The price displayed can sometimes be based on either the bid price (the highest price a buyer is willing to pay), the ask price (the lowest price a seller is willing to accept), or a composite of the two. Different providers may use different conventions, which can slightly impact the recorded daily high and low prices.

Adjustments for Corporate Actions
Events like stock splits, reverse splits, and dividend payouts require adjustments to historical prices to create a continuous, comparable chart. Different data providers may employ slightly different methodologies, timing, or factors when applying these adjustments. This is particularly noticeable in older historical data, where varying adjustment techniques can lead to more significant price differences compared to unadjusted raw data or data adjusted by another provider. For futures data, different methods of "rolling" contracts can also lead to price variations.

Inclusion of Extended Trading Hours
With modern electronic trading, many markets have significant price movements during pre-market and after-hours sessions. Some data providers include trades from these extended hours when determining the daily high and low, while others may only use prices from the standard trading session. This decision significantly impacts the recorded daily range. Futures and FX markets, trading nearly 24/7, have similar considerations for what constitutes a "day."

Data Corrections and Updates
Data vendors occasionally identify errors or receive corrected information, leading to updates in their historical databases. These corrections can alter previously reported prices.

Provider-Specific Data Pools
Our chart data originates from paid financial APIs, and our source has changed over time since 2005 to adapt to market and provider changes (e.g., switching from providers like Alphavantage when their services, such as real-time data, changed). Currently, our data is supplied by APIs including Alpaca. A common cause of price differences, which can occasionally be significant (not just minor variations), is that providers like Alpaca may base their data primarily on their own order books or a limited number of direct feeds, rather than aggregating from the entire market like platforms such as TradingView. This impacts daily highs, lows, and closes. The data on our charts and performance reports are presented exactly as received from our current API source (Alpaca).

While we strive for consistency and accuracy using our current data sources, these factors collectively explain why you may observe variations in historical price data when comparing our charts to other platforms or historical records.