"reached its highest point" is a grammatically correct phrase and can be used in written English.
Example: The stock market reached its highest point in history, causing investors to rejoice.
The stock price has climbed handsomely in recent years; it reached its highest point ever in August: $67 a share.
"When it reached its highest point, we were very concerned," Finn said, noting there wasn't much else they could do to protect the historic home.
Despite the glut of workers, the share of small businesses saying they couldn't find the talent they wanted was generally rising from December 2009 until September 2012, when it reached its highest point since the recession began five years earlier.
In the Bronx, it may have reached its highest point in the person of a parish priest who walked the street with the lost boys of the community while bullets were flying.
It came as the level of admissions reached its highest point since the peak seen at Christmas, with 420,700 patients – up from 407,000 the previous week.
The relative protein expression level for α-dystrobrevin-2 reached its highest point on day 10 at 175% whereupon it started to decline.
It reached its high point in the 16th century, when it had more than 30,000 inhabitants; glassmaking continues but on a considerably reduced scale.
It could be that his cinema writing reached its high point as the medium itself reached its century in the 1990s, and the millennial moment prompted some of Adair's most inspired work as a historian and critic.
But NASA seems to have reached its high point so far in social media when it comes to the Mars Curiosity rover.
New York minimalism reached its high point in the mid 1970s with two major works by Philip Glass and Steve Reich.
If western liberal democracy reached its high point with the fall of the Berlin Wall, by the end of this year its very survival began to look in doubt.
