what is year over year yoy 
year over year yoy sometimes referred to as year on year is a frequently used financial comparison for looking at two or more measurable events on an annualized basis observing yoy performance allows for gauging if a company s financial performance is improving static or worsening for example you may read in financial reports that a particular business reported that its revenues increased for the third quarter on a yoy basis for the last three years investopedia candra huffunderstanding year over year yoy year over year compares a company s financial performance in one period with its numbers for the same period one year earlier this is considered more informative than a month to month comparison which often reflects seasonal trends common yoy comparisons include annual and quarterly as well as monthly performance benefits of year over year yoy yoy measurements facilitate the cross comparison of sets of data for a company s first quarter revenue using yoy data a financial analyst or an investor can compare years of first quarter revenue data and quickly ascertain whether a company s revenue is increasing or decreasing by comparing the same months in different years it is possible to draw accurate comparisons despite the seasonal nature of consumer behavior this yoy comparison is also valuable for investment portfolios investors like to examine yoy performance to see how performance changes over time uses of year over year yoy yoy comparisons are popular when analyzing a company s performance because they help mitigate seasonality a factor that can influence most businesses sales profits and other financial metrics change during different periods of the year because most lines of business have a peak season and a low demand season for example retailers have a peak demand season during the holiday shopping season which falls in the fourth quarter of the year to properly quantify a company s performance it makes sense to compare revenue and profits yoy it s important to compare the fourth quarter performance in one year to the fourth quarter performance in other years suppose an investor looks at a retailer s results in the fourth quarter versus the prior third quarter in that case it might appear that a company is undergoing unprecedented growth when seasonality influences the difference in the results similarly in a comparison of the fourth quarter with the following first quarter there might appear to be a dramatic decline when this could also be a result of seasonality yoy also differs from the term sequential which measures one quarter or month to the previous one and allows investors to see linear growth for instance the number of cell phones a tech company sold in the fourth quarter compared with the third quarter or the number of seats an airline filled in january compared with december example of year over year yoy below is apple s income statement from q2 2024 total net sales for the second quarter were 90 8 billion total net sales for the second quarter of 2023 were 94 8 billion this means that apple s net sales in q2 2024 were down 4 3 year over year yoy 1for q2 2024 apple s net income was 23 6 billion which was a decrease compared to its net income of 24 2 billion in q2 2023 this was a 2 2 decrease year over year 1