There is no "standard" way, that would be an HTML tag like we had before that needed no styling. But at the end of the day, it is better this way. We have control over all aspects of each object we intend to display rather than always relying on defaults. This is better for overall user experience, and not quite in the scope of StackOverflow, but marquees in general already fall outside of the scope of good user experience in most cases.
If you would like to dig into it more though, there are some cross browser differences you should pay attention for, and you may need to tweak the width and indents to fit your needs, but this should get you going:
<div class="marquee">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</div>
.marquee {
width: 300px;
margin: 0 auto;
overflow: hidden;
white-space: nowrap;
box-sizing: border-box;
animation: marquee 50s linear infinite;
}
@keyframes marquee {
0% { text-indent: 27.5em }
100% { text-indent: -105em }
}
http://jsfiddle.net/7k5g3hco/