Jon Geenty of the CoinMetrics team showcased why we shouldn't overestimate the impact of Coinbase listing announcements on altcoin performance.
Always keep market sentiment in mind
Mr. Geenty compared three preliminary listing announcements, i.e. posts about the 'exploration' of new assets. The Coinbase team posts announcements of this type to reveal that new coins are under evaluation for listing.
The analyst decided to take an announcement made in a bearish market (in late 2018), a 'flat' market (Summer, 2019) and one which was unveiled this June.
He studied the performance of all of the assets subject to exploration against the U.S. Dollar, Ethereum (ETH), Bitcoin (BTC), Monero (XMR), ZCash (ZEC) and Dogecoin (DOGE) to avoid distorting any trend in the performance of benchmark assets. In 2018, every to-be-listed asset demonstrated relatively pale gains.

The weakest performance demonstrated by the assets in question occurred after the announcement in 2019. The choppy flat of the Bitcoin (BTC) price and the overall market uncertainty erased almost every 'pump' gain that didn't surpass 10% against USD, Bitcoin (BTC) and Ethereum (ETH).
To compare, the last announcement appeared to be a real catalyst. The assets rallied against every benchmark in a matter of days. However, even with this beautiful perspective, the trendy OMG Network Token (OMG) pump looks like an outlier.

Still a good indicator
All in all, the 'Coinbase listing pump' still looks like a reliable representation of short-term runs for the majority of assets. Typically, the price of a token surges by up to 14% against the U.S. Dollar.
Traders should act quickly to take profits from this process. As revealed by this report, most of the time, all gains are mitigated within a 20-day period.
As covered by U.Today Crypto News, the last Coinbase 'exploration' announcement was slammed by Bitcoin (BTC) proponent Max Keiser of Russia Today. He accused the exchange of a 'casino'-like approach and suggested it should be regulated like a gambling platform.