public static bool SuspiciousMovement(string ticker, int newPrice, DateTime quoteTime)
{
PreviousStockPriceInfo lastQuote;
// Find the details of the previous quote for this stock (if any)
if (!findStock(ticker, out lastQuote))
{
// If the stock has not already been "seen" before then we cannot compare the new quote against the last quote
// so just add the stock and return false to indicate that this activity is not suspicious
stockRecords.Add(new PreviousStockPriceInfo(ticker, newPrice, quoteTime));
return(false);
}
else
{
bool isSuspicious = false;
// Scrutinize the data for the current quote and compare it against the values for the previous quote
if (lastQuote.LastPrice > LOW_PRICE && newPrice > LOW_PRICE)
{
if (Math.Abs(lastQuote.LastPrice - newPrice) / (decimal)lastQuote.LastPrice > MOVEMENT_PERCENT)
{
if (quoteTime.Minute - lastQuote.LastQuoteTime.Minute < INTERVAL_MINS)
{
isSuspicious = true;
}
}
}
// Store the details for the new quote and overwrite the details of the previous quote
int location = stockRecords.IndexOf(lastQuote);
stockRecords[location] = new PreviousStockPriceInfo(ticker, newPrice, quoteTime);
return(isSuspicious);
}
}
// Find the last movment for the specified stock and populate lastQuote with the data.
// Return true if a previous quote was found, false otherwise
private static bool findStock(string ticker, out PreviousStockPriceInfo lastQuote)
{
// Retrieve the previous quote for this time from the stockRecords list
lastQuote = stockRecords.Find(item => string.Compare(ticker, item.Ticker) == 0);
// Return a boolean that indicates whether a record was found:
// If no such item was found, the fields in the lastQuote structure will have their default values, and the Ticker field will be null
return(lastQuote.Ticker != null);
}