In modern markets, institutional investors employ agency algorithms that strategically subdivide large orders to minimize the price-impact and signaling of their trades. As a consequence, the daily level of institutional market activity has become increasingly difficult to identify. In this paper, I exploit an intraday artifact caused by the repeated order submission of agency algorithms – Clock-Time Periodicity – to quantify their use and illuminate the trading behavior of the institutional investors that employ them. I show that agency algorithms are utilized on a daily basis and account for an average of 3.1% of trade volume. I show that the arrival of historically informative SEC filings increases the volume of institutional trading. Earnings Announcements and Regulation Fair Disclosure filings have the largest impact, with an increase in institutional trade volume of 13.9% and 2.56% respectively. I present evidence supporting two plausible motivations for the increased activity: a) Urgency and b) Liquidity. First, the increase in institutional volume is contrasted by a stark decrease in the number of limit-orders used to achieve it. An indication that agency algorithms not only trade more but do so more aggressively. Second, on filing dates an increase in institutional volume worsens trade conditions with magnitudes that rival the effect of the news itself. Lastly, the increase in the size of institutional trades is overshadowed by an even larger increase in the size of non-institutional trades. This suggests that the trading behavior of non-institutional traders provides a ‘smokescreen’ for agency algorithms to trade more aggressively while remaining stealthy.