Below are the data of the Ethereum and the Bitcoin over a 5-day period. Maria would like to invest in either of these two cryptocurrencies. She would like you to help her to calculate the 4-day average Amihud illiquidity measure in billions. If Maria wants to invest in a liquid cryptocurrency, which cryptocurrency should she purchase? Assume volume is the dollar trading volume.

Ethereum
Date	Open	High	Low	Adj Close	Volume
26/07/2021	3,866	3,962	3,806	3,830	16,578,095,000
27/07/2021	3,830	3,915	3,661	3,847	15,908,090,000
28/07/2021	3,848	3,888	3,687	3,749	17,386,204,000
29/07/2021	3,747	3,884	3,737	3,878	15,998,757,000
30/07/2021	3,878	4,167	3,833	3,869	20,338,319,000

Bitcoin
Date	Open	High	Low	Adj Close	Volume
26/07/2021	61,610	62,274	60,206	60,892	34,250,964,000
27/07/2021	60,888	61,646	59,164	61,554	29,032,367,000
28/07/2021	61,549	62,615	60,013	60,026	38,055,562,000
29/07/2021	62,043	64,435	61,623	64,262	40,471,196,000
30/07/2021	64,285	66,930	63,011	63,121	40,788,955,000